Bio Review

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Bio Review

Exam Dates: May 17th and 18th

Error bars show range of data or standard deviation

Calculate SD on calculator

SD summarizes spread of values around mean  • 68% +/- 1 SD, 95% +/-2 SD • Flat bell curve = spread out data. • Tall/skinny curve = data closely bunched to mean

SD useful for comparing 2 sample sets: closer means and SD  more likely samples from same population

T-test: Normal distribution, sample size at least 10 • Compare 2 data sets, measure amount of overlap • If t > critical value @ .05  significant difference, null hypothesis should be rejected

• Correlation does not imply causation

Bio Review

Exam Dates: May 17th and 18th

Additional notes:
Experiments • Samples to represent entire population o Sample must be small enough to efficiently get data, but large enough to represent population as a whole. o Nothing is 100% confident. Standard Deviation (SD) • Measures how observations are dispersed around mean. o List numbers:  1,3,4,6,9,19 o Mean:  42/6= 7 o List of deviations: subtract each mean from each #  -6, -4, -1 ,2, 12 o Square deviations:  36, 16, 9, 1 , 4, 144 o Sum of deviations:  36 + 16 + 9 + 1 + 4 + 144 = 210 o Divide by one less than # of deviations:  R-values • To find correlation o +1 = positive correlation o 0 = no correlation o -1 = negative correlation
Cell Theory

1. Organisms are composed of one or more cells. 2. Cells are smallest unit of life. a. Scientists have yet to find a living entity that is not composed of at least one cell 3. All cells come from pre-existing cells. a. Shown up in biology experiments that disprove idea of spontaneous generation

Bio Review

Exam Dates: May 17th and 18th

• Robert Hooke o First described cell in 1665 o Observed cork with microscope built himself

 Antonie van Leeuwenhoek o Observed first living cells o Called them “animalcules” meaning little animals.  Mathias Schleiden o Stated plants are made of “independent, separate beings” called cells o A year later, Theodor Schwann made a similar statement about animals  Louis Pasteur o Life could only come from life o Only exception would be when life first appeared on Earth’s surface. Exceptions to Cell Theory  Skeletal muscles have muscle fibres which have a membrane but contain hundreds of nuclei  Fungi have hyphae with similar thread-like structures

• Unicellular organisms carry out all functions of life including: o Metabolism o Response o Homeostasis o Growth o Reproduction o Nutrition

A molecule = 1 nm Thickness of cell membrane = 10 nm Viruses = 100 nm Bacteria = 1μm Organelles = up to 10 μm Eukaryotic cells = up to 100 μm

1 millimeter (mm) = 103 meters 1 micrometer (μm) = 103 millimeters 1 nanometer (nm) = 103 micrometers

Bio Review

Exam Dates: May 17th and 18th

• • • • •

Take a measurement of drawing (width or length) Take this same measurement of specimen Remember to convert units if needed to Place your values into equation Magnification = length of drawing / length of actual specimen

Conversion of units: 1 centimeter = 10-2 meters 1 millimeter = 10-3 meters 1 micrometer = 10-6 meters 1 nanometer = 10-9 meters

Increase in size, increase in metabolic demands. • SA  more SA, faster intake • Volume  material made and used in cell affected with change Ratio: • SA: volume ratio decreases with larger cell o Too small of a ratio  cannot meet demands

Multicellular organisms show emergent properties • Cells for tissues  tissues form organs  organs form organ system  organ systems form multicellular organisms • Cells working together that makes an organism function

Differentiation: • All cells of organisms contain all genes of organism o Different genes activated in different cell types  Gene that produces keratin will be active in hair and nail cells  Gene expression is regulated during transcription This makes cells develop in different ways


Bio Review

Exam Dates: May 17th and 18th

• Tissues of body need to be replaced such as skin o Stem cells can produce wide range of cells by differentiating along different pathways  Pluripotent  Retain ability to divide/produce different cells . o For example, one type of stem cells in bone marrow produce a variety of red and white blood cells.

Therapeutic use of stem cells: • Bone marrow transplants o Give rise to red blood cells, white blood cells and platelets • Treat people who have certain types of cancer (Leukemia) o Chemo kills cancer cells and normal cells in bone marrow o Patient can’t produce blood cells o Before treatment, can undergo bone marrow harvest or get from matching donor o Stem cells removed from bone marrow using a needle inserted into pelvis o After chemo patient has bone marrow transplant o Stem cells transplanted back into patient through a drip o Transplanted stem cells get back to bone marrow o Start to produce healthy blood cells o Without, patients would only be able to take low doses of chemotherapy which could lower chances of curing disease


Bio Review

Exam Dates: May 17th and 18th

Prokaryotic cells • Lack membrane, smaller than eukaryotic. o Less than one micrometre in diameter. • • Thought to be first cells to appear on earth. Still play large role today. o i.e. Bacteria.

In cell • Cell wall: o Protects/maintains shape of cell. o Composed of carbohydrate-protein complex: Petidoglycan. o Additional layer allows bacteria to attach to things such as teeth, etc. • PM: o Controls movement of materials (nutrients and waste) in and out of cell. o Plays role in binary fission. • Pili: o Hair-like growths on outside of wall. o Used for attachment. Main function: Joining bacteria cells in preparation for transfer of DNA sexual reproduction. Flagella: o Longer hair like growths used for cell motility.

• •

Ribosomes: o Protein synthesis. High protein production  more ribosomes present. Nucleoid Region: o Only single, long, continuous, circular thread of DNA. o Region in control of cell and reproduction.

Cytoplasm: o Contains:   Enzymes to catalyze reactions of metabolism Ribosomes

Binary Fission:

Bio Review •

Exam Dates: May 17th and 18th

Asexual cell division: o DNA copied o 2 daughter chromosomes attach to different regions of PM. o Cells divide into 2 identical daughter cells. o Includes elongating of cell and separation of membrane.


Eukaryotic Cells Liver cell:  Free ribosomes o very small structures (about 80S) that carry out protein synthesis o found floating in cytoplasm and attached to rough ER o composed of RNA and protein o larger in eukaryotic cells than prokaryotic cells o Eukaryotic ribosomes are composed of two subunits o Synthesize proteins, translate mRNA  Endoplasmic reticulum o Network of channels that stretch from nucleus to PM o Transport materials through cell o Advantage of having ribosomes attached to ER: Proteins synthesized by ribos transported by ER to be parts of cell membranes, enzymes for cell or messengers between cells. o Smooth ER:

Production of membrane phospholipids

Bio Review    

Exam Dates: May 17th and 18th Production of sex hormones Breaks down harmful substances Stores calcium ions Transports lipid based compounds Aid liver cells in releasing glucose into blood when needed

 Lysosome:

o Single membrane bound organelles produced by Golgi apparatus  Contain strong hydrolytic enzymes  Break down biological molecule o Contain up to 40 different enzymes o Involved in breaking down materials brought into a cell via phagocytosis o Can also break down worn out cell parts that are no longer working  Golgi apparatus o Composed of many flattened sacs called cisternae which are stacked on top of each other o Collects, packages, modifies and distributes materials (proteins) for secretion o Close to ER to receive products to be transported by ER o Close to PM so it can discharge materials needed outside cell  Mitochondrion o Very large, double membrane bound rod-shaped o Scattered in cytoplasm and contain their own DNA o Outer membrane is smooth, inner membrane is highly folded into cristae  Cristae increases SA of inner mitochondria for cellular respiration o Function: Cellular respiration  converts glucose to ATP o Size/ability to produce energy (ATP)  mitochondria have own ribosomes o High #s in cells with high energy needs  Nucleus o DNA in double membrane or nuclear envelop o Double membrane allows DNA to remain separate from rest of cell and carry out its functions without interference from other parts of cell o Nuclear membrane contains pores that allow for communication with rest of cell o DNA contained in form of chromosomes within nucleus o Normally located in center of eukaryotic cell but is often pushed to side in plant cells due to large vacuole

Bio Review

Exam Dates: May 17th and 18th

Most cells have one nuclei. Some have multiple nuclei while others have none o No nuclei = cell cannot reproduce o nuclei often have a nucleolus, a dark area inside nucleus where ribosomes are manufactured


FEATURE Genetic material PROKARYOTIC CELLS Contain naked DNA. EUKARYOTIC CELLS Contain four or more chromosomes strands of DNA associated with protein. In double membrane of nucleus. 100s of mitochondria.

Location of genetic material Mitochondria

In cytoplasm nucleoid. No mitochondria. Surface of cell membrane + mesosome produce energy. Ribosomes are smaller (70S). Few or none.

Ribosomes Membrane bound organelles or internal membranes Size

< than 10 micrometers.

Larger ribosomes (80S). Several membrane bound organellesER, Golgi and lysosomes. > 10 micrometers.

Bio Review

Exam Dates: May 17th and 18th

FEATURE Cell wall Chloroplasts Carbohydrate storage Vacuole Shape Centrioles ANIMAL CELL No cell wall, PM only None. Store carbs as glycogen. Not normal, some small vesicles sometimes formed. Rounded shape, flexible PM, can change shape. Centrioles within centrosome area. PLANT CELL Cell wall, PM just inside. Plants that carry out photosynthesis have chloroplasts. Store carbs as starch. One large central fluid filled vacuole. Fixed shapecell wall, box-like Centrioles not within centrosome area.

Extracellular Components • Anything outside PM o Examples:   • Cell wall of plant cell Extracellular matrix of animal cells

Cell wall: o Composed of cellulose microfibrils which form a thick wall around entire cell o Grows with cell o Protects cell, helps maintain shape o Helps cell maintain osmotic balance, protects from too much water entering Extracellular matrix of animal cells: o Composed of glycoproteins and collagen fibres o Forms fibre-like structure that anchors matrix to PM o o Adds strength to PM, allows cell to cell interactions  adjacent cells to attach to one another Supports movement


Bio Review

Exam Dates: May 17th and 18th

• Phospholipid: o Phosporylated side (head)  Hydrophilic  face water o o o Fatty acid chain (tail) Hydrophobic  away from water Makes membrane stable, but flexible Fluid state  change shape easily

• Proteins o Integral

Bio Review

Exam Dates: May 17th and 18th
 Penetrate lipid bilayer from one side to other  Control entry and exit of specific molecules from cell  Hydrophobic and hydrophillic region which helps keep them in place Peripheral     Loosely bound to PM Float in fluid phospholipid bilayer or are attached to an integral protein Known as glycoproteins have a carbohydrate attached Functions in immune responses and are involved in cell to cell recognition Description Exposed on outside, one specific hormone can bind (shape based). Signal transmitted to inside cell. Enzymes in membranes catalyze reactions inside or outside cell, depends on location of active site. Grouped so metabolic pathway occurs. Proteins from adjacent cells hook together  permanent or temporary connections. Forms gap junctions and tight junctions. Involved in cell to cell communication, have attached molecule of carb provides identification label for cell (glycoproteins). Passages through center of membrane proteins. Allows specific substance to pass through from high to low [ ]. Pumps release energy from ATP  moves specific substances across PM. Energy changes shape of protein.


Functions of membrane proteins Hormone binding sites Immobilized Enzymes Cell adhesion Cell to cell communication Channels for Passive Transport Pumps for active transport

Diffusion: • Passive movement • Particles • High to low [ ] region Osmosis: • Passive movement • Water molecules • Across permeable membrane • Low solute to high solute [ ]

Passive transport across membrane: • Membranes = semi-permeable. • Passive transport = no energy used • Simple diffusion:

Bio Review o Molecules through bilayer o Hydrophobic molecules o Water osmosis •

Exam Dates: May 17th and 18th

 If high solute [ ] in cell, water moves into cell Facilitated: o Uses protein channels o Hydrophilic and charged molecules

Active transport: • Substances through membrane using ATP energy • Against [ ] gradient • Protein pumps o Transports certain substances  Control what enters and leaves

Transport of materials in cell: • Synthesized proteins to rough ER  can be modified • Vesicles carry proteins bud off rough ER  go to Golgi apparatus  further modification • Vesicles fuse with membrane  expel contents outside cell

Fluidity of membrane: • Phospholipids  not solid o Changes shape, vesicles fuse to it. o Endocytosis and Exocytosis 

Exocytosis: vesicle fuses to membrane, expels stuff, membrane returns to original state Endocytosis: pulls PM inward  pinches off vesicle from membrane

Cell cycle: • Interphase: o G1 (gap phase 1) cell grows o S synthesis, genome replicates o G2 more growth, separates replicated genome • Mitosis: o Prophase

Bio Review o Metaphase o Anaphase o Telophase • Cytokinesis: o Cytoplasm divides o Creation of 2 daughter cells   Animal: cell is pinched Plant: plate formed

Exam Dates: May 17th and 18th

Tumors: • Uncontrolled cell division • Any organ or tissue in any living organism

Mitosis: • Prophase o Supercoiling of chromos  Visible under microscope o Centrioles to opposite poles o Spindle fibres appear o Nuclear membrane disappears • • • Metaphase o Chromatids align, spindle fibres attach to centromeres Anaphase o Centromeres break, sister chromatids (chromosomes) to opposite poles Telophase o Nuclear membrane reforms Chromos  chromatin (less visible) o Spindle fibres disappear

Cytokinesis division

Mitosis  2 genetically identical nuclei • DNA replication  chromos produces identical copies (chromatids) • Chromatids separate copy of each chromo in each daughter cell


Bio Review

Exam Dates: May 17th and 18th

Growth: increase in SA and volume of cell Tissue repair: cells divide to replace damaged/lost cells Asexual reproduction/ embryonic development: single celled organisms reproduce via mitosis

Chemistry of Life 3.1.1
Most frequently occurring elements in living things: • Carbon • Hydrogen • Oxygen • Nitrogen

Elements need by living organisms: • Sulfur • Calcium • Phosphorus • Iron • Sodium

• Sulfur: o In proteins o Synthesis of 2 amino acids Calcium: o In bones Messenger  binds calmodulin and other proteins that regulate transcription Phosphorus: o In nucleic acids

Bio Review • Iron: o In hemoglobin

Exam Dates: May 17th and 18th

Synthesis of cytochromes  used for electron transport in aerobic cell respiration Sodium: raises solute [ ] in cytoplasm water can enter by osmosis


Properties of water: • Thermal: o Large heat capacity Lots of energy required to increase temperature Due to H-bond strength Remains stable • Beneficial for habitat o High boiling point, low freezing point    100 C • H-bond strength • Still livable  Less dense as it freezes • Ice forms on surface first • Still livable o Evaporates o Cohesion:  H-bonding holds molecules together • Moves up plants • Surface tension o Solvent:   Polar • Things dissolve in it

• Coolant: o Evaporation of water cools body and plant leaves surfaces (sweat/transpiration)

Bio Review

Exam Dates: May 17th and 18th

• Metabolic reactions: o Polarity  things can dissolve in it • Transport medium o Polarity  things can dissolve in it (ie. blood and sap can transport stuff)

Organic: found in living organisms, contain carbon • Exceptions : o Carbon dioxide o Carbonates o Hydrogen carbonates Inorganic: don’t contain carbon

Amino acid:

Glucose :

Bio Review

Exam Dates: May 17th and 18th

Ribose :

Fatty Acid:

• Monosaccharides: o Single unit sugar:  Glucose  Fructose  Galactose • Disaccharides: o 2 monos bonded together  Maltose  Lactose  Sucrose • Polysaccharides: o Many monos:    Starch Glycogen Cellulose


Bio Review

Exam Dates: May 17th and 18th

Functions of sugars: • Animals: o Glucose energy source o Lactose energy to newborns until weaned o Glycogen energy stored in muscles and liver • Plants: o Fructose:  Sweet taste in fruits  Attracts animals to eat and disperse seeds o Sucrose  energy source o Cellulose  fibres, strengthen

Condensation: • Joins 2 molecules together  water molecule formed as result o Amino acids together  polypeptides

o Monosaccharides polysaccharides

Bio Review
o Glycerol  fatty acids  triglycerides

Exam Dates: May 17th and 18th

• All biological molecules formed by condensation rxns. • Dehydration synthesis Hydrolysis: • Reverse of dehydration synthesis o Molecule of water added to break bonds

Functions of lipids: • Energy storage: o In form o foils in plants o Fats in animals • Heat insulation: o Heat loss reduced by fat layer below skin • Buoyancy: o Lipids less dense than water  animals float

Carbs vs. Lipids: • Energy stored in both forms o Carbs  short term energy  4 cal/g  Easier, more effecient digestion  Stored and released faster  Polar + soluble, transport easier o Lipids long term  9 cal/g • Less dense for same amount of energy

Bio Review

Exam Dates: May 17th and 18th Non-polar  do not interfere with osmosis

Protein structure: • Primary: o Amino acid sequence o Peptide bonds o Determined by base sequence of gene that codes for protein

• Secondary: o α-helix coils and β-pleated sheets o Regular repeating structures o H-bonds between O and carboxyl group of one amino acid and H in amino group of the other

Bio Review

Exam Dates: May 17th and 18th

• Tertiary: o 3D o After translation o Polypeptide folding up o Stabilized by intermolecular bonds b/t amino acids     Ionic H-bond Disulfide (bridges) Van der Waals forces

Quaternary: • 2+ polypeptides linked together to form single protein o Insulin o Collagen o Hemoglobin • All types of bonding • Prosthetic group: o Example: 4 polypeptides linked to heme group o Conjugated proteins


Bio Review Protein shape: • Fibrous: o Long + narrow o Many polypeptide chains o Insoluble in water
 

Exam Dates: May 17th and 18th

Collagen  Human connective tissue Actin found in muscle, use in muscle contractions

• Globular: o Rounded 3D o Mostly soluble
 

Hemoglobin  delievering oxygen Insulin regulates blood glucose

Amino acids: • Polar vs. non-polar  depends on R group • Distribution of amino acids in protein molecule influences: o Protein location in cell o Protein function o Determining specificity of enzymes  • Polar properties determine shape of active site Polar: o Hydrophilic R group o In hydrophilic regions of membrane proteins  Create channels for polar substances Non-polar: o Hydrophobic R group

Function Example Details Shape

Bio Review Structural Collagen

Exam Dates: May 17th and 18th Strengthens bones, tendon and skin. In spaces between their cells (extra cellular matrix). Fibrous

Transport Movemen t Defence


Iron containing protein binds with oxygen in Globular the lungs, transports it to body tissue. Fibrous Globular

Myosin and Myosin + actin  causes contraction of actin muscle fibres  movement. Immunoglobin Antibodies  fight bacteria and viruses. Infinite number of antibodies can be produced from protein because it can be varied.

Nucleotide: • Sugar: deoxyribose • Base • Phosphate group

Bases: • Adenine • Guanine • Cytosine • Thymine

Linkage of DNA nucleotides: • Covalent bond formed between sugar of one nucleotide, phosphate group of another.

Double helix: • 2 nucleotide strands o Connected by covalent bond • 2 strands themselves connected by H-bonds between bases of strands • A T, G  C

Bio Review

Exam Dates: May 17th and 18th


DNA Structure: • 2 strands o One end: phosphate group attached to carbon atom 5 of deoxyribose (5’ terminal) o Other end: hydroxyl group attached to carbon atom 3 of deoxyribose (3’ terminal)

Bio Review • Strands run in opposite directions o Antiparallel

Exam Dates: May 17th and 18th

• Adjacent nucleotides attached together via bonds between phosphate group of one and C3 of deoxyribose of other. • Bases link with H bonds o A and G = purines  2 rings o T and C = pyrimidines  1 ring o AT  2 H-bonds o GC 3 H-bonds

Nucleosomes: • Forms histones to help coil up and fit inside nucleus. • 2 molecules each, 4 different histones o DNA wrapped around 8 histones twice • Negative charge DNA attracted to positive charge histones • One DNA strand links nucleosomes • 5th histone attached to help wrapping

Bio Review

Exam Dates: May 17th and 18th

Nucleosomes help to supercoil chromosomes and regulate transcription.

Not all base sequences in DNA translated: • Genomes: o Highly repetitive  5-200 bases repeated up to 10 000 times  5-45% of euk DNA • Unique genes translated  only small portion of euk DNA

Euk genes contain exons and introns • Exons: fragments of genes coding regions • Introns: fragments of genes  non-coding regions o Used in transcription and translation

Replication: • Semi-conservative  both DNA molecules produced formed from an old strand and a new strand • Unwinding of double strand  breaking H-bonds between bases o Enzyme helicase • Separate strands templates for new strands • Free nucleotides form H-bonds with complimentary base pairs on template strand o DNA polymerase • New DNA strands rewind into double helix • New DNA strand identical to initial one

Complementary base pairing: • Conservation of base sequence: o A T, CG  ensures each new strand is complementary to template o Ensures 2 identical DNA molecules formed from identical parent strand

Bio Review

Exam Dates: May 17th and 18th

DNA replication is semi-conservative.

DNA Replication: 5’  3’ direction

DNA Replication: • Enzyme helicase uncoils DNA double helix o Creates template strands • Topoisomerase helps relieve tension ahead of replication forks caused by unwinding • RNA primase adds short sequence of RNA to template strand o RNA acts as primer for DNA polymerase III to bind
• DNA polymerase III adds nucleotides to template strands (5’  3’ direction)

Nucleotides have 3 phosphate groups  deoxyribonucleoside triphosphates o 2 phosphate groups break off to release energy
o • Antiparallel strands means only 5’  3’ replication possible

o Leading strand: goes with replication fork o Lagging strand: replicated in Okazaki fragments in opposite direction • DNA polymerase I removes RNA primers + replaces them with DNA • DNA ligase joins Okazaki fragments together to make continuous strand o Forms sugar-phosphate backbone  new strand of DNA


Bio Review

Exam Dates: May 17th and 18th

DNA replication initiated at many points in euk chromosomes.

DNA 5 carbon sugar deoxyribose Thymine Double helix 1 type Can’t leave the nucleus Much longer RNA 5 carbon sugar ribose Uracil instead of thymine Single strand 3 types: m-RNA, t-RNA, r-RNA Leaves the nucleus Shorter strands

DNA Transcription: • Formation of mRNA strand  complementary to DNA strand • Uncoiling DNA double helix o RNA polymerase • Free RNA nucleotides form RNA strand using DNA template strand o Complementary base paring  thymine replaced with uracil • Strand elongates then separates from DNA template • Template reforms double helix

Codons: • Codon = triplet bases • Codes for particular amino acid, 64 total • Amino acids link to form proteins o DNA/RNA regulate protein synthesis Genetic code = codons within DNA and RNA composed of triplets of bases

Translation: • Proteins synthesized • mRNA binds to small subunit of ribosome • tRNA have specific amino acid attached that corresponds with anticodons • tRNA molecule binds to ribosome to match mRNA codon o Complementary base pairing  forms H-bond

Bio Review

Exam Dates: May 17th and 18th

• Another tRNA attaches  corresponding amino acids form peptide bond

• First tRNA detaches as 3rd attaches and all tRNA shift along chain • Polypeptide chain formed

Relationship between gene and polypeptide: • Genes store info needed to make poly peptides • Stored as codons (triplets of bases) • Codons code for amino acids • Transcription and translation decode and produce polypeptide chains  protein synthesis.

• Transcription: 5’3  3’ direction

• Antisense strand is template DNA  transcribed • Sense strand  same base sequence as mRNA

Transcription: • mRNA produced • RNA polymerase recognises sequence of DNA promoter • Promoter tells RNA polymerase where to start transcription • Transcription initiated with binding RNA polymerase • RNA polymerase uncoils DNA  separates into 2 strands • One strand = template • RNA polymerase uses free nucleoside triphosphates to build mRNA • Nucleoside triphosphates bond to complementary base pairs on template o Uracil with adenine • RNA polymerase forms covalent bonds between nucleotides o Moves along DNA elongating mRNA until reaches terminator DNA sequence • RNA polymerase released from DNA

Bio Review • mRNA separates from template • DNA rewinds

Exam Dates: May 17th and 18th

Euk RNA needs removal of introns to form mature mRNA

tRNA: • Different types, each recognised by tRNA-activating enzyme • Enzyme binds specific amino acid to tRNA using ATP • tRNA has specific structure  double stranded section (base pairing H-bonds) and loops • Anticodon loop contains anticodon + 2 other loops • Nucleotide sequence CCA for @ 3’ end  attaches to amino acid • Each has slightly different chemical properties and 3D structure so activating enzyme can attach correct amino acid o 20 different enzymes  20 different amino acids • Enzymes attach specific amino acid to tRNA with matching anticodon creating high energy bond  later used to bind amino acids to polypeptide chain o ATP used

Ribosome: • Proteins and ribosomal RNA • 2 subunits  large and small • Surface has 3 sites for tRNA to bind to  only 2 can bind at once • Bonding site for mRNA too

Bio Review

Exam Dates: May 17th and 18th

Translation consists of: • Initiation • Elongation • Translocation • Termination

Translation 5’  3’ direction

7. 4.5

Translation: • Initiation: o Amino acid methionine combines with mRNA and small subunit of ribosome o Ribosome reads AUG start codon o Large subunit binds to smaller one along with initiation factor proteins • Elongation: o tRNA bring matching amino acids to mRNA ribosomal complex  Matching anticodons to codons o Elongation factors bind tRNA to A site Initiator mores to P site  peptide bond formed b/t amino acids o Large subunit moves over small subunit  as 3rd tRNA attaches, 1st shifts to E site and is released

Bio Review • •

Exam Dates: May 17th and 18th

Translocation: (technically occurs during elongation) o Movement of tRNA from site to site as polypeptides are built Termination: o 3 stop codons appear in A site o Release factor protein enters A site and catalyzes release of complete polypeptide o Released polypeptide signals separation of ribosomal subunits and mRNA strand o Polysome = sting of ribosomes all going through translation on one mRNA strand

Free ribosomes synthesize proteins for use within cell Bound ribosomes synthesize proteins for secretion/lysosomes

Enzyme: globular protein which acts as catalysts for chemical rxns. Active site: region on surface of enzyme where substrates bind that catalyzes a chemical rxn involving substrates.

Enzyme-substrate specificity: • Active site of enzyme is specific to its substrates o Precise shape • • Enzymes can only catalyze certain rxns Substrate must fit active site shape and be chemically attracted to it Lock and key

Effects on enzyme activity: • Temperature: o Activity increases with temperature  doubles every 10 degrees  Molecules move faster  more collisions o At certain point (past 37 degrees) enzymes denature and stop functioning

Heat causes vibrations in enzyme  breaks bonds within it

pH: o Optimum pH = most efficient o Activity decreases as it diverges o Acidic and basic environments denature enzymes Substrate [ ] o Activity increases with [ ]

Bio Review

Exam Dates: May 17th and 18th

 More random collisions o Reaches max when all active sites are taken up

Denaturation: changing structure of enzyme so it can no longer carry out its function

Use of lactase: • Lactose = sugar in milk o Broken down by lactase in glucose and Galactose

Some people don’t have lactase lactose intolerance Milk that is lactose-free produced: o Adding enzyme lactase to milk  breaks down lactose

Metabolic pathways consist of chains and cycles of enzyme-catalyzed rxns.

Induced-fit model: • Substrate doesn’t fit perfectly into active site at first • Binds to active site  changes shape of active site to fit perfectly • Explains why some enzymes can bind to many different substrates o Different but similar substrates can bind thanks to shape change

Bio Review

Exam Dates: May 17th and 18th

Enzymes lower activation energy of chemical rxns that they catalyze: • Reactants need activation energy before they can undergo rxn o Needed to break bonds in reactants

Rxn energy released as new bonds form  most bio rxns = exo o Energy released > EA o Enzymes lower EA so rxns occur more easily

Inhibitors: inhibit enzyme activity • Competitive: o Structurally similar too substrate of enzyme  binds to active site  Prevents substrate from binding to site until inhibitor is released o Effects can be reduces by increasing substrate [ ]  more substrate will bind to active sites than inhibitor  Example: malonate • Like succinate  Krebs cycle of aerobic respiration • Non-competitive: o Not similar to substrate  don’t bind with active site

Bio Review

Exam Dates: May 17th and 18th

o Bind with separate site that changes conformation of active site o Substrate may still bind, but enzyme cannot catalyze rxn as fast  Increasing substrate will not prevent inhibitor from binding • Example: ATP accumulates and binds, lowers rate of rxn less ATP produced.

Metabolic pathways: • Many chemical rxns catalyzed by enzymes • End-product inhibition: non competitive inhibitors o Last rxn in pathway inhibits enzyme that catalyzes first reaction  Binds to allosteric site  active site changes shape • Unlikely for substrate to bind  Active site returns when inhibitor is released • Advantage: o Excess end-product will shut down pathway bc it inhibits first enzyme pathway o Prevents formation of intermediates

Cell respiration: controlled release of energy from organic compounds to form ATP.

In cell respiration: • Glycolysis breaks down glucose • Forms pyruvate and small ATP yield

Anaerobic cell respiration: • In humans: o Pyruvates stays in cytoplasm o Coverted into lactate then removed from cell • In yeast: o Pyruvate converted into CO2 and ethanol  no ATP produced

Aerobic cell respiration: • Pyruvate taken into mitochondria if oxygen present

Bio Review

Exam Dates: May 17th and 18th

Pyruvate broken into CO2 and H2O o Large amounts of ATP released

Oxidation: loss of e- from element, usually gaining O or losing H Reduction: gain of e-, losing O or gaining H

Glycolysis: First stage of cell respiration • Phosphorylation: o 2 phosphate groups added to glucose from 2 ATP molecules  Produces fructose 1,6-biphosphate • Lysis: o Fructose 1,6-biphosphate splits into 2 molecules of glyceraldehyde-3phosphate (G3P) • Oxidation: o 2 atoms H removed from each G3P o Energy released by oxidation used to add phosphate group to G3P o NAD+ = H carrier, accepts H atoms lost ATP formation: o 2 pyruvate molecules formed  2 phosphate groups removed from each molecule  Phosphate groups given to ADP  ATP Occurs in cytoplasm  2 ATP used, 4 produced 2 NAD+ coverted to NADH + H+ 2 pyruvate formed •

Bio Review

Exam Dates: May 17th and 18th


Aerobic respiration: • Glycolysis can take place without oxygen  anaerobic respiration o Pyruvate produced cannot be oxidised further

Aerobic  when pyruvate is oxidized in mitochondria o First rxn= link rxn  Mitochondria cells take up pyruvate formed from Glycolysis

Bio Review 

Exam Dates: May 17th and 18th Oxidative decarboxylation: enzymes in matrix of mitochondrion remove H and CO2 from pyruvate • H to NAD+ Results in acetyl group formation • Acetyl group accepted by CoA  acetyl CoA

Krebs cycle: • Acetyl group from acetyl CoA  4 carbon compound o Result: 6 carbon compound

 CoA released 6-C compound  oxidative decarboxylation o Result: 5-C compound CO2 released  NAD+ NADH + H+ 5-C compound oxidative decarboxylation o Result: 4-C compound  CO2 released  ]NAD+  NADH + H 4-C compound undergoes substrate-level phophorylation o ADP ATP o Oxidation twice  One H accepted by NAD+  NADH + H+  Other H accepted by FAD  FADH2 o 4-C compound ready to accept new acetyl group o Cycle repeated

• •

CO2 removed in rxns as waste product excreted from body Oxidations release energy stored by carriers that accept H Energy used later by e- transport chain

Bio Review

Exam Dates: May 17th and 18th

Electron transport chain: Oxidative phophorylation • In inner membrane of mitochondria  chain of e- carriers (proteins) • NADH donates 2 e- to first carrier in chain • e- pass along chain giving up energy as the pass from carriers o Redox rxns •

Enough energy released to produce ATP via ATP synthase @ 3 locations FADH2 donate e- at later stage than NADH o Only 2 stages where sufficient energy released for ATP production from FADH2 e-

Role of Oxygen: • @ end of e- transport chain, e- donated to oxygen in matrix • Oxygen binds with H+  forms H2O • No oxygen  e- can’t apss through chain  NADH + H+ can’t be reconverted to NAD+  NAD+ would run out and link rxn could not occur

Oxidative Phosphorylation and chemiosmosis: • e- pass through chain + release energy • Energy used to pump H+ against [ ] gradient from matrix into space between inner and outer membranes of mitochondria o Potential energy storage in form of built up [ ] gradient build up

Bio Review •

Exam Dates: May 17th and 18th

Protons brought back to matrix through chemiosmotic channels in synthase molecules • Energy released as protons flow down gradient used by ATP synthase to phosphorylate ADP Chemiosmosis necessary for oxidative Phosphorylation

Structure Outer Membrane Matrix Cristae Inner Membrane Space b/t membranes Function Keeps contents of mitochondria separate from the rest of the cell Internal cytosol-like area has enzymes for the link reaction/Krebs cycle Membrane surrounded tubular regions. Increase the surface area for oxidative phosphorylation . Has carriers of e- transport chain. Contains ATP synthase  chemiosmosis H+ ions (protons) reservoir; high concentration needed for chemiosmosis.

Photosynthesis: conversion of light energy to chemical energy.

Light from sun composed of wavelengths (colours).

Chlorophyll: main photosynthetic pigment.

Chlorophyll can absorb red and blue light more than green: • Green light reflects back  leaves look green

Light energy: • Used to produce ATP • Photolysis: split water molecules o Forms O2 and H2


Bio Review

Exam Dates: May 17th and 18th

ATP and H2 derived from photolysis of water used to fix CO2 + make organic molecules.

Rate of photosynthesis: • Measured in many ways: o Production of oxygen  Plants release oxygen: can be collected and measured o Uptake of CO2  More difficult to measure: • pH of water rises as CO2 is absorbed o Increase in biomass  Batches of plants harvest at series of times: • Biomass calculated  rate increase = indirect measure of rate of photosynthesis

Effects on photosynthesis rate: • Temperature: o Increase = increase in rate until optimum temperature o Decreases quickly after optimum • Light intensity: o Increase= increase in rate until a certain point  Plateaus at max rate o Low+ medium intensity rate directly proportional to intensity CO2 [ ]: o Increase= increase in rate   No photosynthesis at low levels Plateaus at high levels


Bio Review

Exam Dates: May 17th and 18th

Photosynthesis consists of both light-dependent and light-independent rxns

Light-dependent rxns: • Occurs inside chloroplasts o Contain chlorophyll: green pigment in thylakoid membranes o Chlorophyll arranged in photosystems  II and I • Chlorophyll absorbs light energy raises e- to higher energy state o Chlorophyll = photoactivated Non-cyclic pathway: • Starts in Photosystem II o Excited e- passed on from one chlorophyll molecule to next until they reach reaction centre ofphotosystem o Photolysis: e- must be replaced  enzyme splits H2O into 2H+ and O • O2 forms and released as waste product o e- then passed to electron carrier chain in thylakoid membrane

Energy released • Carrier: o PQ o Cytochrome complex

o Chemiosmosis:  Energy used to pump protons across thylakoid membrane into space in thylakoids (proton gradient)

Bio Review

Exam Dates: May 17th and 18th

• •

Protons travel back passing through ATP synthase energy released used for non-cyclic photophosphorylation (ADP ATP) o END non-cyclic photophosphorylation e- from chain accepted by photosystem I replacing previously lost ePhotosystem 1 absorbs light  photoactivated e- become excited again Short chain of e- carriers o Ferredoxin NADP reductase catalyses transfer of e- from ferredoxin to NADP+ in stoma o NADP+ accepts 2 e- and one H+ to form NADPH

Overall produces: NADPH and ATP + oxygen as a by-product  intermediates used in next stage of photosynthesis Cyclic Photophosphorylation: Photosystem 1 only, produces ATP only

Photophosphorylation and chemiosmosis: • Chemiosmosis how phosphorylation of ADP occurs in photosynthesis • Light energy drives chemiosmosis  photophosphorylation o Cytochrome complex H+ pumped to inside of thylakoids during etransport b/t photosystems o [ ] gradient builds  H+ move to stroma through ATP synthase o Energy from H+ moving through ATP synthase produces energy to phosphorylate ADP

Light-independent rxns: • Calvin cycle:

Bio Review o Carbon fixation: 

Exam Dates: May 17th and 18th

 
 

CO2 in stroma (entered by diffusion) reacts with 5-C sugar (RuBP) • Result: 6-C compound • Catalyzed by rubisco 6-C splits into 2 glycerate 3-phosphate Glycerate 3-phosphate reduced to 3-C sugar (triose phosphate) • Energy required provided by ATP/NADPH + H+ 2 triose phosphate react  glucose phosphate Condensation rxn glucose phosphate converted to starch • 6 triose phosphate produced 1 synthesizes glucose phosphate, 5 used to regenerate RuBP Regeneration of RuBP essential: • 5 triose + ATP  3 RuBP

Light Dependent Reaction In thylakoid

Light Independent Reaction In stroma

Bio Review Light energy  ATP and NADPH Photolysis: splits water to provide replacement electrons + H+ also releases oxygen to the atmosphere Photosystems l and ll + two electron transport chains

Exam Dates: May 17th and 18th ATP and NADPH  triose phosphate Returns ADP, inorganic phosphate and NADP to the light dependent reaction Calvin cycle

Features of chloroplast: • Stroma: o Contains many enzymes  Rubisco o Important for the reactions of the Calvin cycle. • Thylakoids: o Large SA for light absorption o Space within allows rapid accumulation of protons • Double membrane: o Isolate contents o Separate from chemically different contents of cell

Action spectrum: • Shows rate of photosynthesis (for each wavelength of light) o Lowest rate: Green o Good rate: Red-orange o Best rate: Violet-blue Absorption spectrum: • Shows % of light absorbed by pigments in chloroplast (for each wavelength of light) o Least absorption: Green  reflected o Good absorption: Red-orange o Best absorption: Violet-blue Spectrums = closely related Difference: no absorption of green-yellow, but still photosynthesis thanks to accessory pigments (like carotene)


Bio Review

Exam Dates: May 17th and 18th

Limiting factors in photosynthesis: • Only one at a time furthest from optimum level at particular time o Example: night = light intensity, day = temp or CO2 [ ] • Light intensity: o Shortage of ATP and NADPH

Products of light-dependent rxns  light-independent rxns can’t occur bc glycerate 3-phosphate can’t be reduced

Temperature: o Enzymes work slower @ low temp o Enzymes no longer effective @ high temp  Calvin cycle rate of rxn slows CO2 [ ]: o Low glycerate 3-phosphate limited

Euk chromosome= DNA and proteins.

Gene: • Heritable factor • Controls specific characteristic Allele: • Specific form of gene • Differs from others by one or a few bases only • Same gene locus as other alleles of gene Genome: • Whole of genetic info of organism

Gene mutation: change to base sequence of gene


Bio Review

Exam Dates: May 17th and 18th

Base substitution mutation transcription and translation: Sickle cell anemia: Normal Gene Codon GAG Mutated gene GTG GUG on mRNA

Transcriptio GAG on mRNA n Translation

Anticodon CUC and Anticodon CAC and amino acid glutamic acid amino acid valine on on tRNA. tRNA. HbS

Haemoglobin HbA Phenotype Effects

Normal donut shaped red Sickle cell shaped red blood cells. blood cells. Carry oxygen efficiently Do not carry oxygen but are affected by efficiently but give malaria. resistance to malaria.

Meiosis: reduction division of diploid nucleus into haploid nuclei

Homologous chromosome: • Chromos with same genes, in same sequence • Different alleles of genes

See 10.1.1


Bio Review

Exam Dates: May 17th and 18th

Non-disjunction: • Anaphase I or anaphase II: chromos do not separate properly • Leads to gametes with too many or too few chromos o Usually die quite fast when missing chromo • With extras can survive Down syndrome: o Trisomie 21  3 chromosome 21 instead of 2  47 total chromos instead of 46 o Leads to complications

Can take place in egg or sperm

Karyotyping chromos arranged in pairs according to size and structure

Karyotyping: • Uses cell collected by: o Chorionic villus sampling o Amniocentesis • For pre-natal diagnosis of chromosome abnormalities

Females: XX chromos Males: XY chromos

Bio Review

Exam Dates: May 17th and 18th

Meiosis: • Interphase: o G1 o S o G2 • Meiosis I: o Prophase I: Chromos coil up tightly visible  Chromos pair up  homologous pairs (tetrad) • Crossing over @ chiasma  exchange of genetic material b/t non-sister chromatids  Nuclear membrane breaks down  Centrioles travel to poles o Metaphase I:

Homologous chromos (tetrads) align  Spindle fibres form and attach to chromosomes o Anaphase I:  Tetrads separated, pulled to opposite poles by shortening spindle fibres  Chromos still sister chromatids, one chromo from each pair at opposite poles o Telophase I:  Nuclear membrane forms around chromos at each pole  Chromos uncoil  Cytokinesis  May enter brief Interphase no replication Meiosis II: o Prophase II:  Chromos recoil  Centrioles move to poles  Nuclear membrane disintegrates o Metaphase II:  Spindle fibres attach to centromeres  Chromos align o Anaphase II:  Fibres shorten  Centromeres split 

Bio Review 

Exam Dates: May 17th and 18th Chromatids to opposite poles

Telophase II:  Nuclear membrane forms around chromatids @ each pole • Chromatid  chromosome  Cytokinesis  Chromos uncoil  Nucleoli form Result: haploid daughter cells

Chiasmata: • Prophase I: o Homo chromo pairs become tightly linked by synapsis o Non-sister chromatids break at exact same location o DNA exchanged

Infinite genetic possibilities: • Crossing over: o Prophase I Exchange of genetic material New combos of alleles • Recombinants different allele combo than either parent  Occurs @ a random point + more than one chiasma is possible Random orientation o Metaphase I  Maternal/paternal chromos can orient toward either pole  223 possible outcomes  

Mendel’s law: • Allele pairs separate independently during gamete formation o Traits transmitted to offspring are independent of one another

Mendel’s law and meiosis: • Metaphase I homo chromo pairs align  random orientation o Either chromo can end up at either pole o Whichever way the pair is facing does not affect which was the other homo chromo pairs are facing

Bio Review •

Exam Dates: May 17th and 18th

Unlinked genes found on different chromos so daughter cells have random assortments of chromos and alleles

Genotype: alleles of an organism Phenotype: characteristics of an organism Dominant allele: same effect on phenotype in homo/heterozygous state Recessive allele: only has effect on phenotype in homozygous state Codominant alleles: pairs that both affect phenotype in heterozygote Locus: position of gene on homo chromos Homozygous: 2 identical alleles of a gene Heterozygous: 2 different alleles of a gene Carrier: has 1 recessive allele that causes genetic disease in individuals that are homozygous for this allele Test cross: testing for heterozygote by crossing with a know homozygous recessive

Monohybrid crossing

Some genes have more than 2 alleles

Codominance+ multiple alleles: Blood types • ABO o A o B o AB


Bio Review

Exam Dates: May 17th and 18th

o O


Sex chromosomes: • Females: XX o Always passes X Males: XY o Passes X or Y Gender depends on which chromo the sperm passes one •

Some genes present in X chromo are absent from shorter Y chromo in humans.\

Sex linkage: • Gene controlling characteristic is located on sex chromo characteristic is associated with gender

Colour blindness and Hemophilia: • Gene carried by X chromo • Female has 2 X chromos so it can be masked by other

Human female can be homo or heterozygous with respect to sex-linked genes

Female carriers for X-linked recessive alleles: • Always heterozygous • Carrier will either pass dominate or recessive allele

Monohybrid crosses with sex-linked genes and blood types.


Bio Review

Exam Dates: May 17th and 18th

Pedigree charts: • Squares = males • Circles = females • Shaded = affected individuals • Unshaded = unaffected individuals Effect of gene: • Most males affected X-linked • 50/50 ratio b/t men + women  autosomal • Dominant disorder one parent must have it • Recessive disorder: neither parent need to have it


Sex chromo determines gender

Bio Review

Exam Dates: May 17th and 18th

Autosomal chromo not sex chromos, other 22 pairs


Linkage group: pair/set of genes on a chromosome that tend to be inherited together

Polymerase chain reaction: • Used to copy + amplify minute quantities of DNA • Only small amount of DNA available but large amount needed to undergo testing • Blood, semen, tissues o Example: crime scenes

Gel electrophoresis: • Fragments of DNA move in electrical field

Bio Review

Exam Dates: May 17th and 18th

Separated according to their size

Gel electrophoresis of DNA used in profiling

Gel electrophoresis application: • Organisms have short sequence of bases repeated many times (satellite DNA) o Vary in length from person to person • DNA copied using PCR and cut into small fragments using restriction enzymes • Gel electrophoresis separates fragmented pieces according to size and charge o Patter of bands on gel different for 2 individuals  Determine paternity  Used in forensics investigations to determine suspects

Find similarities between DNA found at crime scene and suspect. Find similarities between child and possible father.

Complete human genome sequence: • Easier to study gene influence on human development • Helps identify genetic diseases • Allows production of new drugs based on DNA base sequences + structure of coded proteins • More information on origins, evolution and migration of humans

Genetic code= universal: • Genes transferred between species  amino acid sequence of polypeptides stays the same

Gene transfer: • Cloning:

Genetically modified crops:

Bio Review

Exam Dates: May 17th and 18th

Tomatoes: o More tolerant of salt in soil o Delay ripening process o Resitant to herbicides and bacteria Sheep: o Used to produce large amounts of rare biological substances for medicinal purposes  Used to carry gene for human blood protein for clotting  Secrete factor IX in milk which can be purified Possible Harmful Effects Bt toxin/bacterial DNA in genetically modified maize harmful to humans or animals? Other species could be killed/affected. The toxin found in maize pollen  blown onto other plants  feeding insects harmed. Spread of Bt gene pollen cross pollination in some plants but not others some will be resistant, others endangered.

Possible Benefits Less pest damage higher crop yields reduce food shortages. More crop yields  less land needs to be used. Some land could become wildlife conservation areas. Reduce the amount of insecticide sprays expensive and harmful to farmers/wildlife

Clone: group of genetically identical organisms/cells derived from a single parent cell

Dolly the sheep: • Cloned by taking udder cells from donor sheep • Cells cultured in low nutrient medium genes become dormant • Unfertilized egg taken from another sheep • Nucleus of egg cell removed • Egg cells fused with udder cells • Fused cells develop like normal zygotes embryos • Embryos implanted into another sheep • Lamb born genetically identical to sheep from which udder cells were taken

Arguments for cloning in humans Already happens naturally  identical twins Arguments against cloning in humans Psychological problems of identity/ individuality

Bio Review Screening process for genetic diseases easier with embryo cloning Increase IVF success chances if their embryos are cloned

Exam Dates: May 17th and 18th Using differentiated cells = high risk of fetal abnormalities + high rate of miscarriage. DNA of differentiated cells already ageing, clone may grow older faster than usual.

• Large macromolecules are too big to passs through cell membranes Molecule Ingested for of molecule End product of digestion Protein Protein Amino acids Lipids Triglycerides Glycerol and fatty acids Carbohydrates Polysaccharides, Monosaccharides disaccharides, monosaccharide Nucleic DNA/RNA Nucleotides • Food ingeted contains important nutrients for humans that we can’t get from anywhere else o starches/glycogen o proteins o nucleic acid Many rxns need high temperatures unsafe for body Enzymes lower activation energy of reactions  lowers necessary input of heat Enzymes also help hydrolysis rxns


Source Substrate Products Optimum pH Salivary Amylase Salivary glands Amylose (starch) Maltose/glucose Neutral Pepsin (Protease) Stomach cells Proteins (polypeptides) Amino acids Acidic (1-3) Pancreatic lipase Pancreas cells Lipids Glycerol/fatty acids Neutral

Bio Review

Exam Dates: May 17th and 18th


Stomach: • Muscular walls churn to mix food with enzymes secreted from gastric glands o Juice contains pepsin, HCL and mucus from cells of inner lining Pepsin = protease enzyme  most active in low pH  HCL helps degrade food, kills bacteria and makes acidic enviro for pepsin  Mucus prevent stomach damage from HCL • Food temporarily stored in stomach, slowly released into small intestine once it gets soupy (chyme) • Acidic natures ensures most harmful bacteria are killed Small intestine: • Attached to stomach, longest portion of digestive tract • Digestion of macromolecules completed • End products of nutrient digestion also absorbed • Through opening @ beginning the following are released to help enzymes complete nutrient digestion: o Bile from liver/gall bladder

Bio Review o Enzymes from pancreas

Exam Dates: May 17th and 18th

 Trypsin  Lipase  Amylase  Bicarbonate o Enzymes also secreted from glands in walls • Lining of small intestine contains millions of finger-like projections (villi) o Increase surface area for efficient absorption

 Glucose  Amino acids  Fatty acids • Inside villi: capillary bed & lacteal o Digested nutrients diffuse into blood stream or lymphatic system o Changed into energy Large intestine: • Indigestible materials emptied here • Main function is reabsorption of water from indigestible material to form feces • Feces temporarily stored in rectum until expelled through anus • Home to bacteria which helps to produce vitamin K

• • Absorption of nutrients takes place in the small intestine through villi Once absorbed, they are assimilated (become part of tissues) o Person consumes steak, proteins broken down into amino acids, used to build muscles Villi line small intestine, increase surface area for absorption o Contain small protrusion (microvilli), further increase surface area One cell thick layer, easy for diffusion (epithelium ) o Transport across cells of villi assisted by ATP from mitochondria ion cells o Also protein channels in membranes of microvilli, use facilitated diffusion to assist nutrients across o Microvilli membranes have protein pumps which use active transport to move Each villus has blood capillaries and a lacteal in its centre for diffusion into blood stream & lymphatic system

• •


Bio Review •

Exam Dates: May 17th and 18th

Digestive juices secreted into alimentary canal by glands o Salivary o Gastric o Pancreas o Small intestine

Exocrine glands: • Collection of cells to secrete product carried to a specific location by way of duct o Product:   • Protein Enzymes

Features: o Extensive endoplasmic reticulum o Many:  Ribosomes  Golgi bodies  Vesicles/granules  Mitochodria Surround ends of small branches of pancreatic duct  ductile takes secretions to larger and larger ducts until they reach the pancreatic duct Saliva: o Water = Solvent o Amylase o Mucus Gastric juice: o Water = Solvent o Pepsin o HCL o Mucus Pancreatic juice: o Water = Solvent o Amylase o Trypsin o Lipase o Bicarbonate



Bio Review • •
• •

Exam Dates: May 17th and 18th

Specific juices secreted @ specific times for hydrolysis Sight/smell of food triggers nerves which initiate secretion Food enters stomach  receptors in stomach send sensory signals to brain more secretion Distension of stomach (widened from food) hormone gastrin produced  release of gastric fluid

Membrane bound enzymes: • Stay in membranes of cells of inner lining of small intestine o ie. Maltose in inner epithelial cell membranes of villi&microvilli  Floats to active site  Enzyme catalyses hydrolysis rxn o Advantage:   Stays in lumen longer than free floating enzymes Product already in proper place for absorption

• • • Humans do not produce enzyme to digest cellulose We don’t have the same mutualistic microorganisms that produce cellulose like grazers Plant material ends up in feces Fully active protease doesn’t distinguish between proteins & body structure protein Pepsin & Trypsin are synthesized in non chemically active molecular form o Pepsin + 44 additional amino acid = pepsinogen  Contact with HCL cause 44 amino acids to be lost o Trypsinogen in pancreatic juice brought to duodenum of small intestine

• •

Food enters duodenum  enterokinase produced  Trypsinogen converted to Trypsin

• Gastritis & Ulcers cause by: o Helicobacter pylori burrow under mucus layer  infect stomach lining cells o They create ammonia with urease to neutralize acid Antibiotics help long-term gastritis More prone to cancer and common infection

• •

Bio Review

Exam Dates: May 17th and 18th

• • • Lipids = insoluble in water Fluids in canal = aqueous Hydrophilic molecules in hydrophobic solution o Lipids stick together (coalesce)  Low surface area to density ratio Lipase added in duodenum of small intestine o Catalyses hydrolysis of outside molecules of lipid globule Bile produced by liver (stored in gall bladder) have hydrophilic & phobic ends o Go between lipid molecules to separate them (emulsification of lipids)

• •

Increase surface area  easier for lipase to catalyze hydrolysis


Bio Review

Exam Dates: May 17th and 18th

• • • • • • • • • • Villi – provide huge surface area for absorption Epithelium cells – single layer small cells, lots of mitochondria (source of ATP) for active transport across plasma membrane Mitochondria –large numbers, significant demand for ATP in these cells. Microvilli –tiny, finger-like infoldings of the cell surface facing the lumen increase the surface area in contact with material to be absorbed. Pump proteins in the plasma membrane of epithelium cells – actively transport nutrients across the plasma membrane into the villi Mucus from goblet cells in epithelium – lubricates movement of digested food among the villi, protects plasma membrane (of epithelial cells) Tight junctions – bind together individual epithelial cells, only way into the tissues of the body is through the epithelium. Network of capillaries – large surface area for uptake of amino acids, monosaccharides, and fatty acids and glycerol into blood circulation Lacteal – branch of lymphatic system, triglycerides (combined with protein) pass for transport to body cells Pinocytotic vesicles –site of pinocytosis: fluid taken up or released in tiny vesicles, across the plasma membrane of a cell.

Facilitated diffusion: a little assistance to enter and exit cells, transmembrane protein helps by changing shape. Active transport: a lot of assistance to enter cells, energy needed for the subs to penetrate against an unfavourable concentration gradient. Endocytosis: Cells can use their membranes to engulf a particle and bring it inside, engulfing portion of the membrane separates from the cell wall, encases the particle in vesicle.

Small intestine can’t absorb, therefore they are egested:

Bio Review •
• • •

Exam Dates: May 17th and 18th

Cellulose or lignin from plant cell walls Bile pigments from bile colours feces Bacteria  normal tract inhabitants Intestinal cells  break off as food goes through lumen

• • • • •

Major funciton of liver: stabilization of nutrients and storage of nutrients Liver receives blood from hepatic artery (from aorta), hepatic portal vein (from capillaries in villi of small intestine) Hepatic artery = oxygenated blood Hepatic portal vein blood= low pressure, deoxygenated from capillary bed, varies in # of nutrients depending on food and ingestion timing + absorption Blood caried to ‘capillaries’ of liver (sinusoids) where exchange between blood and hepatocytes occur Sinusoids = wider than normal capillaries and have more porous walls  single layer of very thin cells, with many pores or gaps between the cells and no basement membrane Blood drained into hepatic vein blood= low pressure, deoxygenated to the right side of the heart via the inferior vena cava

Liver regulates concentration of solutes in blood • Glucose (Normal level of blood glucose in humans is about 90mg per 100cm3): o Hepatocytes take in extra glucose ingested o Converts it to polysaccharide (used in metabolism) and glycogen to store o This causes drop in concentration of glucose o Respiring body tissues receive glucose supplies from the blood circulation. o As blood glucose falls, glycogen reserves in the liver are converted back to glucose bringing levels back to normal o Regulated by production of insulin + glucagon from pancreas o Insulin stimulates conversion, glucagon reverses it • Amino acids: o Pool of amino acids maintained in plasma, in liver and other tissues  undergoing rapid protein synthesis

Bio Review
o o o o o

Exam Dates: May 17th and 18th Amino acids constantly built into proteins  enzymes, components of membranes, structural components (e.g. collagen fibres, keratin). The demand for new proteins high, most short-lived, body can’t store AAs Excess AAs are deaminated in liver (soluble ammonia is not formed and released in the tissues) Organic acid part of AA removed + respired or converted to fat/carb The fatty acids (and glycerol) combined to form triglycerides  combined with proteins in the liver and stored or transported in the blood plasma, mostly as low-density lipoproteins (LDLs), to the tissues. In tissues lipids stored as food reserves (fat), or immediately broken down and respired as energy


Nutrients stored in live: • Glycogen: polysaccharide carb • Iron: removed and stored after erythrocyte and haemoglobin break down • Vit. A: good vision • Vit. D: added to milk

Liver synthesizes plasma + cholestrol • Plasma proteins: o Albumin  helps regulate osmotive pressure of body fluids o Fibrinogen  soluble blood clotting material o Prothrombin • Globulins  diverse group of blood proteins Cholestrol: o Ingested + absorbed in food, or o Made in liver (synthesized) o Used to produce bile, or o Carried in blood stream

Liver has role of detoxification of: • Ethanol: alcohol • Food preservatives • Pesticides • Herbicides *Renders drugs/toxins that enter blood stream to harmless forms for excretion from blood circulation in kidneys (ie. Antibiotics, penicillin and hormones)

Bio Review

Exam Dates: May 17th and 18th

Erythrocytes: • Short 120 day life span • Replaced by tissue of bone marrow, no mitosis • Close to life span, they weaken + rupture • Millions of haemoglobin cells end up in blood stream • Haemoglobin ingested by Kupffer cells in sinusoids • Haemoglobin broken down: o 4 globin protein hydrolysed into AAs released back into stream for protein synthesis o Iron removed  some stored in liver, some to marrow more blood cells o Haemoglobin without iron = bilirubin (bile pigment)  absorbed by hepatocytes


The coronary arteries supply heart muscle with oxygen and nutrients. Mammals: • Double circulation = Right/left atria and ventricle. • Right atria relaxes  receives deoxygenated blood from superior vena cava atria contracts  pushed through tricuspid valve to relaxed right ventricle  ventricle contracts  pulmonary valves pulmonary arteries into lungs oxygenated  oxygenated blood through pulmonary veins  left atrium relaxes

Bio Review

Exam Dates: May 17th and 18th

and receives blood  atrium contracts  bicuspid (mitral) valve opens left ventricle relaxes, receives blood  ventricle contracts  semilunar valve opens  aorta  body Pacemaker: • Sinoatrial node (SA) in right side of right atrium sends signal of contraction to atrioventricular node which then contracts • Myogenic aka beats itself • Messages to SA from nerves and hormones: o One nerve = messages from medulla to SA node to speed up beating, other slows down beating. o Adrenaline (epinephrine) is carried by the blood, reaches SA node + signals speed up.

Arteries: 1. Thick outer layer of longitudinal collagen and elastic fibres prevents leaks and bulges. 2. Thick wall withstands high pressure. 3. Thick layers of circular elastic fibres and muscle fibres to pump blood. 4. Narrow lumen to maintain high pressure. Veins: 1. Thin layer with few circular elastic fibres and muscle fibres as blood does not flow in pulses. 2. Thin walls so that nearby muscles can help push blood towards the heart. 3. Thin outer layer of longitudinal collagen and elastic fibres as pressure is low. 4. Wide lumen to accommodate the slow flowing blood. Capillaries: 1. Wall is one cell layer thick so distance for diffusion is small. 2. Pores allow plasma to leak out and form tissue fluid. Phagocytes can also pass through pores. 3. Very narrow lumen so that many can fit in a small space.] Blood is composed of plasma, erythrocytes, leucocytes (phagocytes and lymphocytes) and platelets. Nutrients, oxygen, carbon dioxide, hormones, antibodies, urea and heat are all transported by the blood.

Bio Review

Exam Dates: May 17th and 18th

BPM= cardiac cycles per minute Cycle: • Atria contracts (systole) • Higher pressure in atria than in ventricles • Blood to ventricles through atrioventricular valves • Atria diastole, ventricle systole • Higher pressure  valves close • Semilunar valve opens when ventricle pressure > aorta/pulmonary artery pressure • Ventricular diastole occurs + atria fills (diastole)

Left+ Right work at the same time Both chambers in diastole atria pressure slightly > ventricle pressure atrioventricular valves open ventricle pressure < aorta  semilunar valve closed Atrium systole-Ventricle diastole Pressure produced is not very high (atrium wall muscle =thin) no need for great pressure, most blood already in ventricle  moves any remaining blood to ventricle Atrium diastole- ventricle systole beginning of V. Systole ventricle pressure > atrium pressure AV valve closes  aorta pressure >> ventricle  semilunar valve still closed  large volume of blood in ventricle so pressure builds considerably throughout systole  v. Pressure > aorta  semilunar valve opens  contraction finishes  semilunar valve closes  repeat of cycle ****** Lub Dub sound = valves closing

Heart beat controls: Myogenic control: • Resting heart rate, no nervous stimulation • SA node upper wall right atrium close to superior vena cava entrance  modified cardiac muscle cells

Bio Review

Exam Dates: May 17th and 18th

• •

SA node generates action potential on regular frequency  72 beats/min = action potential every 0.8 seconds Potential spread out instantaneously = atria systole Potential reaches AV node (lower wall right atrium, partition between atria) AV node delays action potential for approx. 0.1 second  sends out own AP spreading to ventricles through conducting fibres o Starts @ AV node o Goes down septum o Branches @ various points into thick cardiac muscle tissue

Neurological control: • When myogenic rate does not provide muscles with enough oxygen: o Large arteries + medulla oblongata with chemoreceptor cells respond to increase in carbon dioxide levels (decrease in pH) during physical exertion o Medulla sends APs to SA node so it fires more often o CO2 levels decrease o Chemoreceptors in medulla send APs to SA node to slow heart rate o SA node takes over when rate reaches myogenic pace. • Increase in heart rate due to automatic nervous system (controls physiological changes occurring unconsciously. o ANS functions= antagonistic pair of nerves  One nerve increases rate, other decreases.

Atherosclerosis: • Normal arteries have thick smooth muscle lining + small lumen compared to veins. • Atherosclerosis is slow build-up of plaque (lipids, cholesterol, cell debris, calcium). • Noticeable in med-large arteries • Causes less flexibility to change size in order to regulate blood flow • Inside diameter of blood vessel decreased ability to carry oxygenated blood decreased.

Bio Review • •

Exam Dates: May 17th and 18th

Tissues supplied by artery receive less and less blood Damaged area of blood vessel may form blood clot which can break away and block smaller arteries

Coronary arteries: • If any of the 3 coronary arteries or one or more of their branches become blocked, some portion of heart muscle could be deprived of oxygen • This is when atherosclerosis leads to stenosis of coronary arteries. • Coronary thrombosis (heart attack) occurs when a main branch to a coronary artery gets blocked (often by travelling blood clots). • Symptoms: o Pain in chest towards left arm o Constricting sensation around throat o Breathing difficulties o Severe dizziness/fainting.

Risk factors affecting coronary heart disease  slow progression of plaque build-up in arteries. Factor Info Increasing age 83% individuals who die of CHD = over 65 Heredity Children of ‘rents with CHD more likely to develop it Race Some ethnic groups have higher rates Gender Males have greater risk Factor High blood cholesterol Smoking High blood pressure Sedentary lifestyle Obesity Stressful lifestyle Diabetes Info Constituent of plaque, controlled by diet/medication Doubles risk Makes heart work harder Exercise improves factors affecting CHD Excess weight increase heart workload + other effects May lead to unhealthy habits Minimized when blood sugar levels are carefully monitored.

Pathogen: organism or virus that causes disease • Enters body of host, causes damage

Bio Review •

Exam Dates: May 17th and 18th

Virus, bacteria, protozoa, fungi and various worms

Antibiotics: • Treat bacterial disease • Block/interfere with metabolic pathways of bacterium causing disease without having an effect on human cells o Bacteria= prokaryotic cells o Human= eukaryotic cells • • Interferes with protein synthesis in bacteria or inhibits production of a new cell wall Viruses can’t be treated with antibiotics: o Not cells o Reproduce using metabolic pathways + cell contents of human cells o Any chemical that would kill a virus would also kill human cells

Defence against pathogens: Skin: • Barrier, prevents pathogens entering • 2 layers: o Epidermis tough outer layer o Dermis  constantly replaces epidermis • *Intact* epidermis excellent line of defence • Sebaceous glands in pores of skin secrete lactic acids + fatty acids o Acids = unwelcoming enviro to stop bacteria growth • Mucous membranes around opening with soft skin (vag, urethra, nose, trachea): o Contain lysozyme to kill bacteria o Sticky to trap pathogens o Trachea contains cilia to sweep/push mucus + trapped bacteria out

Phagocytic leukocytes ingestion of pathogens: • Found in blood • Recognize pathogens using protein molecules on surface of cells + viruses o Self or not self • • • Engulf them by endocytosis Lysosomes inside phagocytes digest pathogens Can ingest pathogens in blood and tissue because they can slip through space between cells in walls of capillaries

Bio Review

Exam Dates: May 17th and 18th

Antibodies: • Proteins • Defend the body against pathogens • Bind to antigens on the surface of pathogens • Stimulate destruction of pathogens • Only bind to one specific antigen Antigens: • Foreign substances • Stimulate production of antibodies

Antibody production: • Lymphocytes = leukocytes that make antibodies • 1 type of antibody per, so different lymphocytes required • Y shaped proteins o Antigen-combining binding sites @ ends of Y where antibody attaches to antigen o Found on plasma membrane of lymphocytes

Upon antigen bonding, lymphocyte starts cloning through mitosis  making more specific antibodies to fight pathogen

HIV: • • • • • • Causes AIDS Group of symptoms occurring together Attacks body’s immune system Targets lymphocyte helper T-cells important for producing antibodies Over time, destroys lymphocytes + antibodies are no longer produced Susceptible to disease that would usually be easily controlled but lead to death

Causes: See above Transmission:

Bio Review • • • • • •

Exam Dates: May 17th and 18th

Through body fluids Infected to uninfected person Intercourse + oral sex if there are tears in vag, penis, mouth or intestine Shared hypodermic needles o Blood left on these can contain the virus Mother to child through placenta, cuts during birth or in milk during breastfeeding Blood transfusions/Factor VIII for haemophiliacs

Social Implications: • Grief: relative/friends • Loss of income if infected person is unable to work • Can be refused life insurance • Hard to find partners, employment and housing • Fear in population and reduce sexual activity

Blood clotting: • Broken blood vessel  blood escaping + body open to pathogens • Platelets (small cell fragments in blood)circulate with erythrocytes (red blood cells) and leukocytes in blood plasma • Damaged cells release chemicals that cause platelets to stick to damaged walls, pile up and plug opening • Prothrombin converted to thrombin • Thrombin converts fibrinogen into fibrous protein fibrin • Fibrin catches cell debris and platelets

Principle of challenge and response, clonal selection and memory cells as basis of immunity: • Virus infects body, cells display viral antigens • Macrophages engulf virus and display viral antigen (molecular pieces on cell membrane = antigen presentation) • Macrophages activate Helper-T cells • Helper-Ts activate B cells for specific antigen • B cells divide using mitosis (clonal selection)

Bio Review

Exam Dates: May 17th and 18th

o Antibody-secreting plasma cells: immediately help fight off primary infection o Memory cells: don’t secrete antibodies during first infection, long-lived + remain circulating in bloodstream for a secondary infection B cell clones produce large amounts of antibodies quickly (challenge and response)

Active immunity: due to antibody production by organism once invaded Passive immunity: due to antibodies received from another organism which active immunity has been stimulated • Mother  fetus through placenta • Mother’s colostrums • Antisera (antivenoms) Artificial immunity: vaccine contain antibodies that fight pathogen

See 11.1.2

Production of monoclonal antibodies: • Pure, all the same type • Polyclonal occurs, but it’s hard to separate different types of antibodies being produced • Antigen injected into mouse • Primary response occurs • Blood harvested • B cells produced for desired antibodies • B cells identified + extracted • Need to be kept alive  fused to tumour (myeloma) cells • Individual hybridoma cells cultured in separate containers and tested for particular antibody (ELISA) • Hybridomas grow rapidly and live long, unfused cells die off Use of monoclonal antibodies: • Diagnostic purposes: o HIV o Pregnancy tests o Embryo begins producing HCG hormone which shows up in blood stream and urine

Bio Review

Exam Dates: May 17th and 18th

o Hybridoma produced by injecting lab animal with HCG o Antibodies harvested + bonded to enzyme catalyses colour change when it encounters HCG Treatment: o Cancerous body cells produce cancer cell-specific antigens on cell membranes o Possible treatment = produce monoclonal antibodies targeting cancer-cell antigens o Chemically modified to carry toxin specific for type of cancer cell or radioisotope for pin-point radiation therapy o Advantage: targets cancer cell directly, less toxin/radioisotope needed

Vaccination: • Introduces disabled pathogen to body • Stimulates immune response • Memory cells created circulate in body in case of real pathogen invasion • Makes secondary immune response quicker

Benefits: • Total elimination of disease  small pox • Decrease spread of epidemics and pandemics • Preventative medicine cost-effective approach to healthcare  cheaper than treatment • Vaccinated individuals don’t experience full symptoms Dangers: • Before 1999, vaccines contained toxins • Overload immune system (multiple, short time period, kids) • MMR vaccine may have link to onset of autism (studies don’t support) • Allergic reactions + autoimmune responses Inhaling: • Inhalation, external intercostals contract, rib cage moves up and out • Same time, diaphragm contracts, moves down and flattens • These contraction increase thorax (chest) volume, decrease in pressure in chest • Decrease in pressure in chest cavity  air rushes in from outside until pressure in lungs rises to match atmospheric pressure outside

Bio Review

Exam Dates: May 17th and 18th

Exhaling • Internal intercostals muscles contract, rib cage moves down and in • Abs contract, diaphragm pushed upward into dome shape • Thorax pressure rises, volume decreased • Increased chest cavity pressure causes air to flow out of lungs

Partial pressure: pressure exerted on object by an individual gas, measure of how much oxygen is in a system

H.6.2 Explain the oxygen dissociation curves of adult hemoglobin, fetal hemoglobin and myoglobin.
• • Fetal haemoglobin (HbF) = higher oxygen affinity than adult haemoglobin (Hb): slightly different sequence in amino acid structure. Oxygen dissociation curve of fetal haemoglobin = to left of adult o Oxygen can leave blood in the mother's placenta and travel to the baby's  Haemoglobin of the mother to the baby's haemoglobin. o Baby has no myoglobin  BC of no muscle mass o Adult and fetal haemoglobin = 4 oxygen molecule affinities (the ability to posses 4 oxygen molecules)  4 heme groups containing iron • Explains slight sigmoid shape of the graph

o Myoglobin (delivers extra oxygen to actively respiring muscles) = one affinity (carries one oxygen molecule)

Bio Review  Single heme group •

Exam Dates: May 17th and 18th

The graph of myoglobin to left of haemoglobin o either completely saturated or not o Graph rises steeply up and levels off

H.6.3 Describe how carbon dioxide is carried by the blood, including the action of carbonic anhydrase, the chloride shift and buffering by plasma proteins.
• • • Waste product of cellular respiration Eventually diffuses out of cells and into capillaries or into tissue fluids drawn into capillaries In blood stream, must be delivered to lungs in the following ways: o Less than 10% remains in the plasma as dissolved CO2, carried to lungs o 70% diffuses into red blood cells  20% is picked up and transported by haemoglobin o Most of the CO2 reacts with H20 in the red blood cells to form carbonic acid   Red blood cells contain the enzyme carbonic anhydrase, which catalyzes this reaction Carbonic acid dissociates into a bicarbonate ion and hydrogen ion (H+).

Bio Review  

Exam Dates: May 17th and 18th Hemoglobin (a plasma protein) binds most of the H+, preventing them from acidifying the blood. The reversibility of the carbonic acid- bicarbonate conversion also helps buffer the blood, • • Releases/removes H+ depending on the pH. Chlorine goes into the red blood cells when bicarbonate comes out. o Chloride shift.

Carbon Dioxide o Small percentage of CO2 stays dissolve in blood plasma and is carried to lungs o CO2 will bind with haemoglobin to be taken to lungs, only one per haemoglobin  carbamino haemoglobin  Dissociates in lungs so it can be released, bond with CO2 lowers haemoglobin affinity to oxygen o Majority of CO2 enters erythrocytes to be converted HCO3-, transported in blood plasma Anhydrase • Conversion of CO2 into HCO3- happens in split second once in red blood cells • Erythrocytes contain anhydrase which catalyses a reaction in which CO2 is combined with water to form carbonic acid • Carbonic acid quickly dissociate into HCO3- and H+ • HCO3- produced in red blood cells leave cells via facilitated diffusion thru specialized protein channels • One HCO3•

• •

HCO3- formed must be accounted for or there would be mjr shift in blood pH pH buffering occurs in which some of H+ released from RBC into blood plasma where they bind plasma proteins Plasma proteins act as pH buffers

H.6.4 Explain the role of the Bohr shift in the supply of oxygen to respiring tissues.
• • • The Bohr shift helps the body release more O2 to respiring tissues when the blood pH is more acidic. During exercise, lots of CO2 is produced  results in larger amounts of H+ ions acidify the blood Bohr shift lets the body know it's exercising.

Bio Review
• • • • •

Exam Dates: May 17th and 18th

Haemoglobin dissociate with oxygen in respiring tissues Achieved thru Bohr shift Haemoglobin = high affinity for oxygen but affinity reduced when haemoglobin is in enviro where partial pressure of CO2 is high. Partial pressure of CO2 high in respiring tissues so it binds with hemo When CO2 binds with hemo it causes conformation change which promotes dissociation of oxygen molecules Partial pressure of CO2 low in lungs so oxygen binds with hemo and CO2 dissociates

H.6.5 Explain how and why ventilation rate varies with exercise.
• When you exercise o use more oxygen o produce more carbon dioxide • • Movement of muscles requires use of ATP therefore rate of cellular respiration increases along with the need for oxygen More carbon dioxide in the blood, the pH level lowers. o Normal blood pH is 7.4 (slightly alkaline) and when level drops it is detected very quickly by cells in walls of arteries such as aorta and carotid arteries Medulla oblongata of brain = breathing centre Cells known as chemosensors and once they detect drop on pH they send action potentials (nerve impulses) to the medulla of the brain Medulla oblongata of brain = breathing centre Controls breathing rate and contains same chemosensors as arteries Blood flows thru capillaries in medulla During exercise concentration of CO2 in blood increases

• • • • • •

Bio Review •

Exam Dates: May 17th and 18th

• • • •

Chemosensors in arteries send messages to breathing center which is also monitoring the blood levels In response to increased CO2 levels, medulla sends action potential to diaphragm and intercostals muscles Nerve impulses increase muscular contractions which increases ventilation rate Increased ventilation rate helps remove CO2 from blood and increase the uptake of oxygen Stop exercising, CO2 levels decrease If the level of the pH is too low, impulses sent to the intercostal muscles and diaphragm to increase the rate and depth of lung ventilation.

H.6.6 Outline the possible causes of asthma and its effects on the gas exchange system.

Asthma = Chronic inflammatory disease of airways During an asthma attack, the air passages constrict, Becomes hard to breathe and get enough air into the lungs Asthma attack: muscular bronchi contract excessively , become inflamed and swollen of producing excess mucus Swelling narrows bronchi, gas exchange becomes difficult Effects of asthma include inflammation and constriction of the bronchial tubes, o Wheezing, coughing, and respiratory distress. o Controlled by medication and trying to avoid triggers.

• • • • •

No set pattern: o Allergens:  Pollen  Mould  Animal Dander o Arthropods

Bio Review  Dust mites  Cockroaches Smoke Scented Products Exercise Stress and strong emotions Cold air Some medications + food preservatives Genetic link 

Exam Dates: May 17th and 18th

o o o o o o o

If parents have asthma, children more likely

H.6.7 Explain the problem of gas exchange at high altitudes and the way the body acclimatizes.
• • • • High altitudes mean lower partial pressure of oxygen than @ sea level Common misconceptions: less oxygen by percentage in air @ high altitudes, but the pressure changes so molecules are more spread out Ventilation @ higher altitudes results in less oxygen entering body so haemoglobin is not as saturated with oxygen Mountain Sickness: o Less oxygen entering blood stream, get sick o Symptoms:  Muscular weakness  Vision problems  Fatigue  Nausea  Abnormally high pulse rate  Headaches o Severe sickness can lead to accumulation of fluid in brain/lungs = life threatening

Bio Review o Avoided by gradually ascending o With time:     •

Exam Dates: May 17th and 18th

Increase in RBCs/hemo Increase capillary network in lungs and muscles Increase lung size and surface area Increase myoglobin in muscle tissues

People living permanently at high altitude have greater lung surface area and larger vital capacity than those living at sea level.

Nervous system consists of • • • central nervous system (CNS) peripheral nerves composed of cells neurons o carry rapid electrical impulses.


Nerve impulses conducted from receptors to the CNS by sensory neurons, • • With CNS by relay neurons From CNS to effectors by motor neurons

Resting potential: electrical potential across plasma membrane of cell, not conducting impulse.

Bio Review

Exam Dates: May 17th and 18th

Action potential: reversal and restoration of electrical potential across plasma membrane of cell, as electrical impulse passes (depolarization and repolarization)

1. 2. 3. 4. 5. 6. 7. 8. 9. Resting potential rises above threshold level. Voltage gated sodium channels open. Sodium ions flow into the cell, more sodium channels open. Inside of cell develops a net positive charge compared to the outside and results in depolarization. Voltage gated potassium channels open. Potassium ions flow out of the cell. Cell develops a net negative charge compared to the outside and results in repolarization. Concentration gradients restored by sodium-potassium pumps. Resting potential is restored. Action potential reaches the end of a presynaptic neuron. Voltage gated calcium channels open. Calcium ions flow into the presynaptic neuron. Vesicles with neurotransmitters inside the presynaptic neuron fuse with the plasma membrane. Neurotransmitters diffuse in the synaptic cleft and bind to receptors on the postsynaptic neuron. The receptors are channels which open and let sodium ions into the postsynaptic neuron. The sodium ions cause the postsynaptic membrane to depolarize. This causes an action potential which passes down the postsynaptic neuron. Neurotransmitters in the synaptic cleft are degraded and the calcium ions are pumped back into the synaptic cleft.

1. 2. 3. 4. 5. 6. 7. 8. 9.

Bio Review

Exam Dates: May 17th and 18th

Endocrine system = glands that release hormones, transported in the blood.

Homeostasis = maintaining internal environment between limits • Blood pH • CO2 [ ] • Blood glucose [ ] • Body temp • Water balance

Homeostasis maintains internal environment between limits Negative feedback used to do so. Any change from set point  an opposite change.

Hypothalamus: • Responsible for monitoring temp of blood o 37 degrees
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Fluctuations from set point  hypothalamus sends signals to body parts Restores temp Significant Decrease Skin arterioles decrease in diameter: less blood flow to skin The diameter of the capillaries in the skin can’t change: less blood flows through them prevents heat loss to the external enviro as temp of skin falls.

Significant Increase Skin arterioles increase in diameter: more blood flow to skin. More blood  heat transfer from core of the body to skin. Heat lost to external enviro  cooling

Bio Review down body

Exam Dates: May 17th and 18th

Skeletal muscle stay relaxed  no more heat generated

Shivering  skeletal muscle small rapid contractions to generate heat.

Sweat glands secrete lots of sweat  Sweat glands to not secrete sweat  no makes skin surface moist. water evaporation can occur Water evaporates from the skin cools down the body.

Blood glucose [ ] • No specific set point • Drop and rise through day  related to food consumption o 4-8 millimoles per dm3 of blood • Negative feedback used to keep it there o Responses from target organs affect rate @ which glucose is taken up/loaded in blood Response to blood glucose levels above the set point β cells in the pancreatic islets produce insulin. Insulin stimulates muscle/liver cells  take glucose from blood + convert to glycogen. Glycogen stored in granules in cytoplasm. Other cells stimulated to take glucose use in cell respiration instead of fat. Response to blood glucose levels below the set pointc α cells in the pancreatic islets produce glucagon. Glucagon stimulates liver cells  converts glycogen back to glucose, releases glucose into blood.

6.5.12 Type I diabetes Early onset, during childhood. Type II diabetes Late onset, after childhood.

Bio Review

Exam Dates: May 17th and 18th

β cells do not produce enough insulin. Target cells become insensitive to insulin. Diet by itself can’t control condition. Insulin injections needed. Insulin injections aren’t usually needed. Low carb diet can control the condition.

Hormones are:  Chemical messengers  Produced in endocrine glands  Travel through blood  Affect the target cells  Target cells have special receptors  react to hormones  Significant distance from location of endocrine gland

Type of Hormone Steroid hormone Peptide (protein) hormone Tyrosine derivatives Example Testosterone, estrogen, progesterone Insulin, ADH, FSH, LH Thyroxin

Steroid hormone: (a) Pass straight through the plasma membrane (lipid bilayer membrane), receptor in target cell Directly affect the expression of genes.  Produced from cholesterol, classified as lipid Peptide hormone (b) Attachment to plasma membrane receptor (Glycoprotein) (c) Receptor-Hormone complex (d) Stimulation of secondary messenger in cytoplasm which alters the action of the cell. Hormone Receptor Complex: • Once inside, steroid hormone binds with receptor protein in cytoplasm, hormonereceptor complex formed • Complex passes across nuclear membrane into nucleus, selectively bind to certain genes


Bio Review

Exam Dates: May 17th and 18th

Hypothalamus links nervous and endocrine systems, controls pituitary gland that secretes hormones


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The homeostatic regulation of water (osmoregulation) is brought about by the action of the hormone Anti-diuretic hormone. The hypothalamus is sensitive to changes in plasma concentrations. Neurosecretory cells in the hypothalamus synthesis ADH and transport this along the axon of their nerves for storage in their synaptic knob endings in the posterior lobe of the hypothalamus.

Bio Review

Exam Dates: May 17th and 18th

 

Osmoregulatory sensitive cells in the hypothalamus which are sensitive to plasma concentrations stimulate the neurosecretory cells to transmit impulses to their storage regions in the posterior lobe of the hypothalamus. ADH is secreted and has its target tissue of the Distal Convoluted and Collecting tubules of the kidney. The ADH causes the opening of the Aquaporin (pores) which increases water reabsorption from kidney filtrate.

11.3.1 Define excretion. • The removal of waste products of metabolic pathways from the body. 11.3.2 Draw and label the structure of the kidney.

11.3.3 Annotate a diagram of a glomerulus and associated nephron to show the function of each part.

Bio Review

Exam Dates: May 17th and 18th

Structure Renal artery Renal vein Afferent vessel

Function Carries blood to kidney Carries blood away from kidney

Small branch of the renal artery; carries unfiltered blood to a capillary bed known as the glomerulus Efferent vessel Carries filtered blood away from the glomerulus Peritubular Capillary Bed Surrounds the three part tubule of the nephron and carries (vasa recta) reabsorbed materials away from the kidney Glomerulus Bowman’s Capsule Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting duct A capillary bed in the nephron that filters various substances from the blood (ultrafiltration) Surrounds the glomerulus; receives filtrate from the glomerulus First extension of Bowman’s capsule; most reabsorption of glucose, salt and water occurs here Second part of extension; absorption of water and salt occurs here Last portion of extension; reabsorption of salt Extends into the medulla; reabsorption of salt, urea and water. Absorption of water regulated by ADH.

11.3.4 Explain the process of ultrafiltration, including blood pressure, fenestrated blood capillaries and basement membrane. Ultrafiltration • Occurs in Bowman’s capsule o In cortex of kidney • Blood enters larger afferent arteriole which branches into glomerulus o Unfiltered blood • Leaves through smaller efferent arteriole which causes high pressure in capsule by draining blood • Water, glucose, amino acids, solutes and metabolic waste filtered out of blood o Through fenestrated capillaries in basement membrane

Bio Review

Exam Dates: May 17th and 18th

Podocyte cells which form inner membrane of Bowman’s capsule help to filter  Plasma proteins and platelets are too large and remain in blood stream. • Glomerular filtrate carried through nephron for selective reabsorption through proximal convoluted tubule 11.3.5 Define osmoregulation. Osmoregulation = body’s response mechanisms which attempt to maintain homeostatic levels of water • Controls water balance of blood, tissue or cytoplasm of a living organism • Total water eliminated depends on: o Volume ingested recently o Perspiration rate o Ventilation rate

11.3.6 Explain the reabsorption of glucose, water and salts in the proximal convoluted tubule, including the roles of microvilli, osmosis and active transport. • Filtrate enters proximal convoluted tubule • Blood cells, proteins, other molecules not part of filtrate exit Bowman’s capsule through efferent arteriole o Filtrate contains many valuable substances  Water  Salt ions  Glucose o Reabsorbed by bloodstream in proximal convoluted tubule o Substances taken back into bloodstream through peritubular cap bed • Wall of proximal convoluted tuble = single cell o Interior = lumen

Bio Review
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Exam Dates: May 17th and 18th Filtrate flows within Inner portion of each tubule has microvilli Water Much remains in filtrate Osmosis  hypotonic region to hypertonic region Glucose All reabsorbed into bloodstream Active transport

Salt Ions Majority must leave filtrate to be reabsorbed Actively transported into tubule cells then intercellular fluid outside tubule Taken into peritubular cap bed

Movement of salt ions from filtrate  tubule cells  fluid  cap bed induces water to follow same route

If moved by dialysis or facilitated diffusion, highest percentage reabsorbed = 50%

11.3.7 Explain the roles of the loop of Henle, medulla, collecting duct and ADH in maintaining the water balance of the blood. • Water and remaining dissolved solutes enter descending porton of loop of Henle o Relatively permeable to water o Relatively impermeable to salt ions  Some water leaves tubule • Filtrate enters ascending portion o Impermeable to water o Permeable to salts  Sodium ions pumped to intercellular fluid • Loops extend into medulla o Medulla = hypertonic region with many ions compared to fluids in tubules/ collecting ducts • Fluid moving up ascending loop to distal convoluted tubule still hypotonic • Filtrate enters distal convoluted tubule

Bio Review

Exam Dates: May 17th and 18th

Fine-tuned to reabsorption of solutes o Enters collecting duct Filtrate = hypotonic o This much water can’t leave body  water intake would need to be high, and could not lose water any other way o Some water reabsorbed even though all solutes needed are already reabsorbed Collecting duct somewhat permeable to water o Depends on presence of antidiuretic hormone  ADH secreted from posterior lobe of pituitary gland, circulates in blood stream  Target tissue = kidney collecting ducts • Collecting ducts extend into highly hypertonic medulla o ADH present:  Collecting duct is permeable  Water moves by osmosis to medulla intercellular fluid to peritubular cap bed to bloodstream o ADH not present:  Collecting duct impermeable to water  Water stays in duct with waste solutes  Urine more dilute

11.3.8 Explain the differences in the concentration of proteins, glucose and urea between blood plasma, glomerular filtrate and urine. • Blood plasma = no filtering • Glomerular filtrate = after ultrafiltration, no reabsorption • Urine = after reabsorption and osmoregulation for elimination Molecule Blood plasma (mg Glomerular filtrate Urine (mg 100ml-1) 100ml-1) (mg 100ml-1) Proteins >700 0 0 Glucose >90 >90 0 Urea 30 30 >1800 • Proteins: o Too large to fit through basement membrane o Not part of filtrate or urine Glucose:

Bio Review

Exam Dates: May 17th and 18th

o Not part of filtrate, but active transport in proximal convoluted tubule take all back to peritubular cap bed o None in urine • Urea: o Not toxic unless concentration too high in blood plasma o High concentration in urine due to reabsorption of water  Content magnified by concentration

11.3.9 Explain the presence of glucose in the urine of untreated diabetic patients. • Diabetes= unregulated blood sugar o Due to antagonistic action of insulin and glucagon • Diabetes = abnormally high levels of glucose in blood plasma o Active transport mechanisms have max rate o Glucose is left behind and goes to urine 11.2 11.2.1 State the roles of bones, ligaments, muscles, tendons and nerves in human movement. • Bones: o Framework o Protection of soft tissue/organs o Levers for body movement o Form blood cells in marrow o Storage of minerals  Calcium  Phosphorus • Muscles & Tendons o Tendons = cords of dense connective tissue  attach skeletal muscles to bones o Muscles provide force necessary for movement  Shortening length of fibres/cells • Requires antagonistic pairs • Ligaments & Nerves o Tough band-like structures o Strengthen joint o Provide stability o Have different sensory nerve endings  Proprioceptors in ligaments/muscles allow monitoring of positions of joint parts  Nerves help prevent over-extension

Bio Review

Exam Dates: May 17th and 18th

11.2.2 Label a diagram of the human elbow joint, including cartilage, synovial fluid, joint capsule, named bones and antagonistic muscles (biceps/triceps).

11.2.3 Outline the functions of the structures in the human elbow joint named in 11.2.2. Joint Part Function Cartilage Reduces friction + absorbs compression Synovial fluid Lube to reduce friction, provides nutrients to cartilage cells Joint capsule Surrounds join, encloses synovial cavity, unites connecting bones Tendon Attaches muscle to bone Ligaments Connect bone to bone Biceps Contracts for flexion of arm Triceps Contracts for extension Humerus Lever for anchorage of elbow muscles Radius Lever for biceps Ulna Lever for triceps 11.2.4 Compare the movements of the hip joint and the knee joint. Hip Knee

Bio Review

Exam Dates: May 17th and 18th

Freely movable Freely movable Angular + rotational movements One direction of angular movement Flexion, extension, abduction, adduction, Flexion and extension circumduction and rotations Ball-like surface fits into cup depression Convex surface in concave surface • Flexion : decrease angle between bones • Extension : decrease angle between bones • Abduction: bone movement away from body midline • Adduction: movement of bone toward body midline • Circumduction: distal/far end of limb moves in circle • Rotation: bone revolves around own longitudinal axis

11.2.5 Describe the structure of striated muscle fibres, including the myofibrils with light and dark bands, mitochondria, the sarcoplasmic reticulum, nuclei and the sarcolemma. • Striated muscle cells = skeletal muscle o Muscle cell = muscle fibre  elongated shape  Multiple nuclei just inside plasma membrane • Plasma membrane = sarcolemma o Multiple tunnel-like extensions that penetrate interior of cell  T-tubules  Cytoplasm of muscle fibres = sarcoplasm • Lots of glycosomes  store glycogen • Myoglobin  Sarcoplasmic reticulum = fluid filled system of membranous sacs around myofibrils • Myofibrils = rod-shaped bodies go the length of cell o Parallel to eachother o Closely packed o Many mitochondria squeezed into them

Bio Review
o o

Exam Dates: May 17th and 18th Contractile elements of muscle  band pattern

Connective tissues o Blood vessels + nerves  Penetrate muscle body 11.2.6 Draw and label a diagram to show the structure of a sarcomere, including Z lines, actin filaments, myosin filaments with heads, and the resultant light and dark bands.

11.2.7 Explain how skeletal muscle contracts, including the release of calcium ions from the sarcoplasmic reticulum, the formation of cross-bridges and re-set myosin heads. 1) Muscles contain repeating sarcomeres a. Which contains actin and myosin filaments i. Actin: thin ii. Myosin: thick 2) Arriving action potential causes Ca2+ release a. From Sarcoplasmic reticulum

Bio Review

Exam Dates: May 17th and 18th

3) Ca2+ binds to troponin a. Causing troponin and tropomyosin to move i. Exposing binding sites on actin for myosin 4) ATP binds to myosin heads, realeasing them 5) ATP hydrolysed and split into ADP + Pi 6) Energy causes myosin heads to change shape a. Heads swivel to move actin, releasing ADP + Pi 7) Myosin filaments move actin filaments toward centre of sarcomere 8) Filaments slide, actin/myosin shorten sarcomere

Book: What? 1) Neurotransmitter called acetylcholine release into gap between axon terminal and sarcolemma of muscle fibre 2) Acetylcholine binds to receptors on sarcolemma 3) Sarcolemma ion channels open, sodium ions move through membrane 4) Generates muscle action potential 5) Muscle action potential moves along membrane through T tubules 6) After generation, muscle AP, acetylcholine broken down by enzyme acetyl cholinesterase  ensures one nerve AP causes only one muscle AP 7) Muscle AP through T tubules causes release of calcium ions from sarcoplasmic reticulum  calcium ions flood to sarcoplasm 8) Calcium ions bind to troponin on actin myofilaments  11.2.8 Analyse electron micrographs to find the state of contraction of muscle fibres.

6.6 6.6.1 Draw and label diagrams of adult male and female reproductive systems.

Bio Review

Exam Dates: May 17th and 18th

6.6.2 Outline role of hormones in menstrual cycle, including FSH, LH, oestrogen and progesterone. • 28 days, time to release egg for possible fertilization + implantation into inner lining of uterus o Implantation must occur when uterine inner lining (endometrium) rich with blood vessels (highly vascular) o Highly vascular endometrium maintained without implantation  breakdown of blood vessels • Hypothalamus regulates cycle o Produces GnRH  Targets pituitary gland • Secretes FSH and LH o Target ovaries  FSH stimulates follicle development • Follicles secrete estrogen o Targets endometrium  Estrogen triggers shut down of FSH • Also causes production and secretion of LH ovulation  LH directs follicle cell transformation to corpus luteum • Secrete progesterone/estrogen maintain endometrium  High estrogen/progesterone= decrease GnRH negative feedback

Bio Review

Exam Dates: May 17th and 18th

LH and FSH released less o Menstruation:  Drop in LH/FSH  corpus luteum deteriorates • Slows down estrogen/progesterone production

6.6.3 Annotate a graph showing hormone levels in menstrual cycle, illustrating the relationship between changes in hormone levels and ovulation, menstruation and thickening of the endometrium.

Bio Review

Exam Dates: May 17th and 18th

6.6.4 List three roles of testosterone in males. 1) Determines development of male genitalia during embryonic development 2) Ensures development of secondary sex characteristics during puberty 3) Maintains sex drive of males throughout lifetime

6.6.5 Outline the process of in-vitro fertilization. • FSH injection  ensures Graafian follicle development • Oocytes (eggs) harvested surgically • Collect sperm cells • Sperm and eggs mixed in separate culture dishes • Microscopic observation reveals which ova are fertilized and developing properly • 2 or 3 healthy embryos introduced to uterus o Expensive, too much risk of failure with just 1 • Unimplanted embryos can be frozen for later if needed 6.6.6 Discuss the ethical issues associated with IVF. Pros Enables couples that can’t otherwise have children to have a family Embryos that aren’t healthy can be eliminated Genetic screen possible to eliminate chance of passing some genetic diseases IVF tech will advance and lead to further benefits Cons Embryos produced, but no implanted are either frozen or destroyed Complex legal issues over use of frozen embryos when couples split Genetic screening could lead to choice of only desirable characteristics Some reproductive problems genetically pass, IVF bypasses matures way of decreasing genetic frequency Multiple births are more likely than with natural conception

Bio Review

Exam Dates: May 17th and 18th

11.4 11.4.1 Annotate a light micrograph of testis tissue to show the location and function of interstitial cells (Leydig cells), germinal epithelium cells, developing spermatozoa and Sertoli cells. Structure Function Lumen of seminiferous tubule Spermatids Spermatogonia Sertoli cells Leydig cells capillaries Germinal epithelium cells Opening of the seminiferous tubule Haploid male gamete (sperm) Immature male gamete Nurture the developing sperm Secrete testosterone Supply blood to tissue of the testis Diploid cells on the outer layer of the testis; develop into spermatocytes

Bio Review

Exam Dates: May 17th and 18th

11.4.2 Outline the processes involved in spermatogenesis within the testis, including mitosis, cell growth, the two divisions of meiosis, and cell differentiation.

11.4.3 State the role of LH, testosterone and FSH in spermatogenesis. FSH stimulates meiosis of primary spermatocytes. LH stimulates testosterone production. Testosterone stimulates final meiosis II and differentiation of spermatids into mature sperm cells.

Bio Review

Exam Dates: May 17th and 18th



Bio Review

Exam Dates: May 17th and 18th

11.4.6 Draw and label the structures of a mature sperm and egg.

11.4.7 Outline the role of the epididymis, seminal vesicle and prostate gland in the production of semen. Epididymis: sperm mature and develop motility Seminal vesicles: mucus to protect sperm in vagina, some nutrients (sugars) Prostate: slightly basic fluid for protection, mineral nutrient, highest volume of fluid 11.4.8 Compare the processes of spermatogenesis and oogenesis, including the number of gametes and the timing of the formation and release of gametes. Oogenesis Spermatogenesis One secondary oocyte per cycle Germinal cell produces 1 gamete Gametes are very large One gamete released during ovulation: day 14 In ovaries Ovulation releases a secondary oocyte Egg production stops at menopause Eggs form during fetal development Millions of sperm daily Germinal cell produces 4 gametes Gametes are very small Millions of gametes released in ejaculation In testes Spermatozoa released during ejaculation Sperm production continues all through life Sperm formation begins during puberty

11.4.9 Fertilization: • Sperm binds to receptor of zona pellucida of egg • Triggers acrosomal rxn • Exocytosis from acrosome releases hydrolytic enzymes break down zona

Bio Review
• • • •

Exam Dates: May 17th and 18th

Membrane proteins of sperm fuse to membrane of egg o Depolarizes membrane Ca+ release from plasma membrane stimulates meiosis II in nucleus Cortical granule fuses with egg plasma membrane re o No polyspermy Nucleus of sperm posted into egg cytoplasm

11.4.10 Outline the role of HCG in early pregnancy. Prevent deterioration of corpus luteum + promote growth needed to produce estrogen and progesterone which help to maintain endometrium with embryo embedded 11.4.11 Outline early embryo development up to the implantation of the blastocyst. • Fertilization zygote with diploid number of chromos • Mitosis as it travels through oviduct • Divides to become embryo of 2 cells then again to 4 • Continues until it forms blastocyst o While this is occurring embryo is traveling towards uterus o Blastocyst implants itself in uterine lining 7 days after fertilization 11.4.12 Explain how the structure and functions of the placenta, including its hormonal role in secretion of oestrogen and progesterone, maintain pregnancy. Placenta: • Lifeline b/t mother + baby • Disc shaped connected to baby by umbilical cord o 2 fetal blood vessels for material exchange o 185mm in diameter, 20mm thick • Oxygen for metabolic processes • Nutrient for growth + development • Progesterone for maintaining pregnancy • Removes waste ie. CO2 11.4.13 Fetus supported by amniotic sac and fluid. 11.4.14 Materials exchanged between the maternal and fetal blood in the placenta. 11.4.15 Outline the process of birth and its hormonal control, including the changes in progesterone and oxytocin levels and positive feedback. • 9 months progesterone makes sure uterus develops properly

Bio Review

Exam Dates: May 17th and 18th

• •

• •

Progesterone normally high drop indicates onset of labour Increase in oxytocin follows induces labour uterine wall contractions Contractions more oxytocin Cervix dilates and becomes thinner Amniotic sac bursts 10cm dilation baby pushed out through vagina Placenta and sac come out after

96 98 101 102 Plat Structure and Growth Tissue in stem:

Bio Review

Exam Dates: May 17th and 18th

Distribution of tissue in leaves:


Non-vascular land bryophytes o No conducting tissues o Small o Grow close to ground   Mosses Liverworts

Seedless vascular o Vascular tissues o Don’t produce seeds

Bio Review    • Horsetails Ferns Club mosses

Exam Dates: May 17th and 18th

Seeded vascular o Extensive vascular tissue o Most species of plants o Seeds contain:    Embryo Nutrient supply Protective coat

Angiosperms flowering o Seeds develop inside protective structure 

Maple trees Oak trees Water lilies

Gymnosperms non-flowering o Seed don’t develop in enclosed structure  Conifers

Monocots vs. Dicots • Cotyledon= seed leaf o First leaf to emerge from seed   One leaf = monocot Two leaves= dicot

Bio Review

Exam Dates: May 17th and 18th

Structure Leaf ventilation Distribution of vascular tissue Number of cotyledons Floral organs Roots Pollen

Dicotyledonous Plants Veins are usually netlike Vascular tissue arranged in a ring Two cotyledons Floral organs found in multiples of four or five Tap root present with lateral branches Pollen grains with three openings

Monocotyledonous Plants Parallel veins Vascular tissue is scattered One cotyledon Floral organs usually in multiples of three Fibrous root system (no main root) Pollen grains with one opening

Plant tissues • Angiosperms: o 3 tissue types formed from meristematic tissue   Composed of small cells similar to stem cells in animals Divide then one cell specializes and others remain

Bio Review

Exam Dates: May 17th and 18th

Types of Tissues Description Dermal tissue A protective outer coating that protects the plant from harmful agents such as pathogens. The dermal tissue can also help prevent water loss and often contains specialized structures for specific purposes. This tissue is composed of thin walled cells that play a role in storage, support, secretion and photosynthesis. This tissue consists of xylem and phloem. They are responsible for conducting water from the roots to the leaves along with water and dissolved minerals. They also provide support and protection for the plant.

Ground tissue Vascular tissue

Leaf tissue:

Bio Review

Exam Dates: May 17th and 18th

Tissue Upper cuticle

Function Aids in reducing water loss by decreasing transpiration and protects against insect invasion Upper epidermis This tissue is made up on a thin layer This tissue also aids in reducing of cells which do not contain water loss, allows light to pass chloroplasts and they are through to the palisade layer, transparent. Found below the prevents gas exchange and cuticle. secretes the waxy cuticle that covers the leaf. Palisade layer The area is called the palisade The palisade layer is responsible mesophyll. A densely packed area for photosynthesis. Due to its of long cells which contain high location in the upper portion of the numbers of chloroplasts for leaf maximum light can be photosynthesis. It is located near theabsorbed top of the leaf (and under the upper epidermis) for absorption of sunlight Spongy layer This area is known as the spongy The spongy mesophyll is located mesophyll and it contains loosely below the palisade mesophyll and packed cells with spaces of air in the spaces between the cells allow between. The cells contain only a for the exchange of gases. Some few chloroplasts. photosynthesis also occurs here. Lower epidermis This tissue contains stomata or stomal pores which are openings on the bottom surface of the lower epidermis. Each stoma is surrounded by a guard cell that controls the opening and closing of the stoma. Veins Distributed throughout the leaf often near the middle in order to be near all cells. Lower cuticle Not a tissue......a waxy covering on the surface of the leaf. Usually thinner than the upper cuticle. Located just below the spongy mesophyll to allow for optimum exchange of gases. The lower surface of the leaf receives less light and heat which helps prevent water loss from the plant. Transports the products of photosynthesis and raw materials. Aids in reducing water loss by decreasing transpiration and protects against insect invasion

Location and Structure Not a tissue......a waxy covering on the surface of the leaf

Bio Review Roots:
• •

Exam Dates: May 17th and 18th

Absorb water and mineral ions from the soil Anchor the plant to the ground Sometimes store nutrients o Epidermis (protection) o Cortex (conduction of water from soil o Endodermis (surrounds vascular tissue) o Vascular tissue (xylem and phloem)

Bio Review Root systems:

Exam Dates: May 17th and 18th


Large group of thin roots spread out in the soil and do not contain a main root.

Taproot o Main vertical root with a few branches

Transport • • • • • Some hyphae grow into plant roots and transfer mineral ions to root of plant For mineral ions the plant provides, fungi If minerals can’t pass the lipid bilayer the use of transport proteins may be required to pump ions across the plasma membrane This is also a form of active transport and require use of energy Specific transport pumps for certain ions o Potassium ions enter root cells through specialized transport proteins known as K channels • Mineral ions are brought into the root cells by proton pumps which are transport proteins found in the plasma membranes of the root cells


Transpiration Pull: • • Water moves into mesophyll from xylem vessels filled with water. Water molecules have strong cohesion forces

Each water molecule pulls next molecule in stream constant flow of water up xylem and into mesophyll cells. [Transpiration pull]

Cohesion and Adhesion

Bio Review

Exam Dates: May 17th and 18th

Water molecules also have strong adhesive properties.
o o

Cohesion = attraction between molecules of same kind Adhesion = attraction between 2 different types of molecules.

Adhesion between walls of the xylem cells and water molecules assists water movement up the xylem vessels.

Potassium and Turgor
• • •

Gain and loss of turgor in guard cells controlled by transport of K ions. Water moves when K ions are epumped into the guard cells (active transport) or diffuse out of the cells (passive transport). Waxy cuticle surrounds endodermis of leaves helps reduce water loss.

Abscisic Acid

Plant hormone causes K ions to rapidly diffuse out of guard cells surrounding stoma. When K ions diffuse out, water leaves  guard cells collapse and close stoma Produced in roots in response to lack of water in soil. Hormone travels to leaves to have effect on guard cells.

• • •

Types of Plants

Mesophytes o Typical terrestrial plant o Adapted to average water supply conditions

Bio Review

Exam Dates: May 17th and 18th

Effects of transpiration: Environmental Factor Light Temperature Wind Humidity Soil water Carbon Dioxide Effect Open stoma in leaves with to light, allows diffusion of CO2 into plant. Increase transpiration bc of open stoma. Temp rises, rate of evap rises increased transpiration Wind/air currents move humid air away from leaves, [ ] gradient maintained so water keeps diffusing out of leaf. Decrease in humidity, increase transpiration  water evaporates into dry air faster. Water [ ] low in soil, guard cells close, transpiration decrease High CO2 [ ] surrounding leaves, guard cells lose turgor stoma closes.


Low water supplies

Adaptations: Adaptation Reduced leaves Reduced # of stoma Stoma in Pits Description of Effect

Leaves= reduced surface area and #  reduces transpiration Fewer stoma than terrestrial plantsreduce water loss Stoma also located inside pits  increase humidity surrounding it  reduce water loss. Thickened waxy cuticle Waxy cuticle thicker  prevents water loss Rolled leaves Rolled up leaves  lower surface stoma inside roll  decrease transpiration Spines Leaves become spines  further decrease SA for evap CAM physiology Alternate form of photosynthesis  allows stoma to close during day when water evap is highest and open during the night for gas exchange.


Aquatic environments.


Second type of vascular tissue in plants

Bio Review

Exam Dates: May 17th and 18th

Living cells Responsible for moving organic molecules in various directions through plant

Sieve Tube Members
• •

The living cells in phloem = sieve tube members + companion cells. Sieve tube member connected to another via sieve tube plates forms sieve tubes. Pores in sieve plates allow mvmnt of organic molecules + water through plant.

Companion Cells

Connect to sieve tube members by plasmodesmata narrow bridges connect cells + allow material transport

Translocation • • Mvmnt of organic molecules “Source” to “sink” direction o Source: plant organ producing organic molecule o Sink: organ where food is used or stored   

Roots Buds Stems

 

Seed Fruits

Some structures function as both @ different times.
o o

Summer: bulb/tuber = sink Early Spring: source

Bio Review

Exam Dates: May 17th and 18th

Origin of the Earth Organization: • • • Organisms= organized Monomers/single molecules need to be joined in order to form polymers Polypeptides = polymers, necessary to build complex compounds like proteins

Reproduction • • • Water • • • Tendency yo depolymerise molecules Many organic compounds dissolve in water Difficult for molecules to organize into polymers To be “alive” it must reproduce Self replicating molecules required DNA common and complex, organic molecules

“These short ones aren’t very interesting”

Species and Speciation • Gene Pool: all genetic info present in reproducing members of a population at a given time o Large gene pools in populations with lots of genetic variance • Allele freq. measures proportion of specific variation of a gene in a pop o Percentage o Snapshot of alleles at that time o Proportions may change over generations

Bio Review

Exam Dates: May 17th and 18th

o Changes with immigrations and emigrations  • •

If a gene pool is modified, some degree of evo has occurred

Gene pools tend to remain constant over time, but not always Mutations cause formation of new alleles, old ones can vanish with passing of the last organisms carrying it Result of evo natural selecting favours certain genes over other, continuation of those genes

Species: • Basic unit of classifying organisms o Set of characteristics which all organisms of same species share    

Physiological/morphological, seen and measured Ability to interbreed and produce fertile offspring Genetic difference from other species Common phylogeny

Members of separate but similar species can reproduce  zonkey, infertile offspring

Challenges: o Populations that could interbreed and be separated by long distances o Classify pops that could breed but reproduce asexually?

Infertile individuals?

o In vitro? • Some members of same species can be stopped from reproducing::
o o

Geographical Isolation land/water prevents m and f finding each other Temporal Isolation Incompatible time frames so pops don’t encounter one another  Plants release pollen at different times, hibernation in mammals

Bio Review

Exam Dates: May 17th and 18th Behavioural Isolation lifestyle habits not compatible  Courtship displays in birds


Hybrids reproductive challenges

• •

Haploid cells = one set of chromosomes Polyploidy = cell contains three or more sets of chromosomes o 3n is triploid o 4n is tetraploid o 5n is pentaploid

• •

Cell division doesn’t separate copies of chromos Common in plant cells Polyploid plant usually vigorous and produce large fruit/food stoage organs and more resistant to disease

Speciation: • When evolving pop changes to point where original pop offspring can’t be produced o Extra chromos lead to more freq. errors in replication o One pop of plan 3n, another 4n, each plant evolves differently o Eventually, pops end up so dissimilar, no longer considered same species Allopatric Speciation: • New species form from existing species because of physical barrier separation

Convergent evolution • • Entire organisms, not just physical features

Bio Review

Exam Dates: May 17th and 18th Tasmanian wolf marsupial looked and behave much like wolves/dogs from other continents

Divergent evolution Gradualism • • Transitional stages b/t major stages in phylogenic line Bc we don’t see rapid evolution happening today, we can conclude it’s gradual

INSERT PLANT SCIENCE, EVOLUTION and SPECIATION Hardy-Weinburg • • Alleles can be studied in a population and their success or failure in terms of the proportion they are found in within a gene pool can be studied The Equation: o Pop size = 1 o Dominant allele frequency = p o Recessive allele frequency = q o Frequency of both alleles must always equal 1 (the population) •

1= p+q

Random fertilization occurs, the chance of inheriting 2 dominant alleles = p x p Chance of inheriting 2 recessive = q x q Expected frequency of homozygous genotypes would be p2 and q2 Also chance of inheriting heterozygous genotype = 2pq Sum of all frequencies = 1

• •


Applications: o Results of a survey of a pop show genotypes fit predictions made by Hardy-Weinberg equation then pop follows H-W principle

Bio Review • Assumptions: o Pop must be large o Mating = random within pop o Allele freq = constant over time o No mutation o No immigration or emigration o No allele-specific mortality

Exam Dates: May 17th and 18th

Assessment Statement: Calculate allele, genotype and phenotype frequencies for 2 alleles of a gene, using H-W equation Phylogeny and Systematics • • • • • Classification= valuable in identifying organisms, suggesting evolutionary links Allows prediction of characteristics shared by members of a group Unknown organisms easily identified if you already have an organized data base Classification keys created by scientist help identify See evolutionary relationships w/ classification o Orgs grouped tgthr have similar anatomical features (homo structure) o Shared characteristics help see how orgs evolve from ancestors o Characteristics shared by orgs w/in group expected to be in other related species Biochemical evidence in Evolution: • • • • • DNA + Protein structures provide evidence for evo theory+ common ancestry All known organisms on Earth use DNA, universal genetic code can be mixed Polypeptides = 20 AAs AAs = left or right handed depending on how their atoms are attached Living orgs use left AAs

Bio Review Phylogeny
• •

Exam Dates: May 17th and 18th

Study of evo history/past of species *MISSING SLIDE Past based on examination of anatomical features, recently past anatomy to examine molecular similarities/differences using proteins/DNA

Not been helpful at all: Do not try to guilt trip me Do not try to remind me of anything school or scholarship related unless I ask you to Do not bring up my bedroom

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