Biology Chapter 4
Content
2/9/2011
Organization of the Cell
Chapter 4
Cell Theory
Cells are basic units of organization and function in all living organisms (2) All cells come from other cells
(1)
All living cells have evolved from a common ancestor
Learning Objective 2
•
What is the relationship between cell organization and homeostasis? homeostasis?
1
2/9/2011
Homeostasis
Cells have many organelles, internal organelles, structures that carry out specific functions, that help maintain homeostasis
•
KEY CONCEPTS
•
Cell organization and size are critical in maintaining homeostasis
Plasma Membrane
•
Plasma membrane
• • • •
surrounds the cell separates cell from external environment maintains internal conditions allows the cell to exchange materials with outer environment
2
2/9/2011
KEY CONCEPTS
Eukaryotic cells are divided into compartments by internal membranes • Membranes provide separate, small areas for specialized activities
•
Learning Objective 4
What methods do biologists use to study cells? • How are microscopy and cell fractionation used?
•
Microscopes
Light microscopes • Electron microscopes
•
•
superior resolving power
3
2/9/2011
Microscopes
Cell Fractionation
Cell fractionation
• •
•
purifies organelles to study function of cell structures
Cell Fractionation
4
2/9/2011
Learning Objective 5
•
How do the general characteristics of prokaryotic and eukaryotic cells differ? • How are plant and animal cells different?
Prokaryotes
•
Prokaryotic cells
• • • • •
No internal membrane organization nuclear area (not nucleus) cell wall ribosomes flagella
Prokaryotes
5
2/9/2011
Eukaryotes
•
Eukaryotic cells
• • •
membranemembrane-enclosed nucleus cytoplasm contains organelles cytosol (fluid component)
Chromatin Nucleolus Nuclear envelope Nuclear pores Nucleus Golgi complex Membranous sacs of Golgi
Plasma membrane Lysosome Nuclear envelope Cristae Ribosomes
Rough ER Rough and smooth endoplastic reticulum (ER) Smooth ER Centrioles Mitochondrion Fig. 4-8, p. 83
Plant Cells
•
Plant cells
• • • •
rigid cell walls Plastids i.e. chloroplasts & chromoplasts large vacuoles no centrioles
6
2/9/2011
Mitochondrion
Cristae Membranous sacs Golgi complex
Cell wall Plasma membrane Vacuole
Chloroplast Granum Stroma Rough ER Ribosomes Smooth ER
Nucleus
Nuclear envelope Nucleolus Nuclear pores Chromatin Rough and smooth endoplasmic reticulum (ER)
Fig. 4-7, p. 82
Learning Objective 6
•
What are the three functions of cell membranes? membranes?
Cell Membranes
Divide cell into compartments Vesicles transport materials between compartments • Important in energy storage and conversion • Endomembrane system
• •
7
2/9/2011
Learning Objective 7
What are the structures and functions of the nucleus? nucleus?
•
The Nucleus
•
Control center of cell
•
genetic information coded in DNA double membrane communicate with cytoplasm
•
Nuclear envelope
•
•
Nuclear pores
•
Nuclear Structures
•
Chromatin
•
DNA and protein DNA condensed for cell division ribosomal RNA synthesis ribosome assembly
•
Chromosomes
•
•
Nucleolus
• •
8
2/9/2011
The Nucleus
KEY CONCEPTS
•
Eukaryotic cells have nuclei containing genetic information coded in DNA
Learning Objective 8
•
What are the structural and functional differences between smooth ER and rough ER? ER?
9
2/9/2011
Endoplasmic Reticulum (ER)
•
Network of folded membranes
•
in cytosol lipid synthesis calcium ion storage detoxifying enzymes ribosomes on outer surface assembles proteins
•
Smooth ER
• • •
•
Rough ER
• •
ER
Learning Objective 9
•
Trace the path of protein synthesis:
• •
•
synthesis in the rough ER processing, modification, and sorting by the Golgi complex transportation to specific destinations
10
2/9/2011
The Golgi Complex
Processes proteins synthesized by ER • Manufactures lysosomes • Cisternae
•
•
stacks of flattened membranous sacs
Transport Vesicles
Formed by membrane budding • Move glycoproteins
•
• •
from ER to cis face of Golgi complex Carry modified proteins from trans face to specific destination
Polypeptides synthesized on ribosomes are inserted into ER lumen. Ribosomes Sugars are added, forming glycoproteins. Rough ER Transport vesicles Glycoprotein deliver glycoproteins to cis face of Golgi. Glycoproteins modified further in Golgi. Glycoproteins move to trans face where they are packaged in transport vesicles. Glycoproteins transported to plasma membrane (or other organelle). Contents of transport vesicle released from cell. Plasma membrane
cis face
trans face
Golgi complex
Fig. 4-14, p. 92
11
2/9/2011
KEY CONCEPTS
•
Proteins are
• • • •
synthesized on ribosomes processed in the endoplasmic reticulum processed by the Golgi complex transported by vesicles
Learning Objective 10
•
What are the functions of lysosomes, lysosomes, vacuoles, vacuoles, and peroxisomes? peroxisomes?
Other Organelles
•
Lysosomes
•
enzymes break down structures store materials in plant cells produce and degrade hydrogen peroxide (catalase) catalase)
•
Vacuoles
•
•
Peroxisomes
•
12
2/9/2011
Learning Objective 11
Compare the functions of mitochondria and chloroplasts • How is ATP synthesized by each of these organelles?
•
Mitochondria
•
Site of aerobic respiration • Double membrane
• •
inner membrane folded (cristae) (cristae) matrix (cristae and inner compartment) programmed cell death
•
Important in apoptosis
•
Outer mitochondrial membrane
Inner mitochondrial membrane
Matrix Cristae
0.25 µm Fig. 4-19, p. 95
13
2/9/2011
Aerobic Respiration
Breaks down nutrients using oxygen Energy from nutrients packaged in ATP • CO2, H2O produced as by-products by• •
Plastids
•
Plastids
• •
organelles that produce and store food in cells of plants and algae plastids that carry out photosynthesis
•
Chloroplasts
•
Chloroplast Structure
•
Stroma
•
fluidfluid-filled space enclosed by inner membrane of chloroplast stacks of membranous sacs (thylakoids) (thylakoids) suspended in stroma
•
Grana
• •
14
2/9/2011
Outer membrane
Inner membrane
Stroma
1 µm
Intermembrane Thylakoid space membrane Thylakoid lumen
Granum (stack of thylakoids)
Fig. 4-20, p. 96
Photosynthesis
•
Chlorophyll
• •
green pigment in thylakoid membranes traps light energy
•
Light energy converted to chemical energy in ATP
•
used to synthesize carbohydrates from carbon dioxide and water
Aerobic respiration Mitochondria (most eukaryotic cells)
Photosynthesis Chloroplasts (some plant and algal cells) Light
Glucose
Glucose
Fig. 4-18, p. 95
15
2/9/2011
KEY CONCEPTS
•
Mitochondria and chloroplasts convert energy from one form to another
Learning Objective 12
•
What are the structures and functions of the cytoskeleton? cytoskeleton?
The Cytoskeleton
• •
Microtubules
•
hollow tubulin cylinders actin filaments important in cell movement strengthen cytoskeleton stabilize cell shape
Microfilaments
• •
•
Intermediate filaments
• •
16
2/9/2011
Microtubules
Microfilaments
Intermediate Filaments
17
2/9/2011
Cytoskeleton
Centrosome
•
Usually contains two centrioles • Each centriole has 9 x 3 arrangement of microtubules
Centrioles
18
2/9/2011
KEY CONCEPTS
The cytoskeleton is a dynamic internal framework that functions in various types of cell movement
•
Learning Objective 13
•
How do cilia and flagella differ in structure and function?
Cilia and Flagella
•
Cilia and flagella
• • •
thin, movable structures project from cell surface function in movement
•
Cilia are short, flagella are long
19
2/9/2011
Cilia
Learning Objective14
•
Describe the glycocalyx, extracellular glycocalyx, matrix, matrix, and cell wall
Cell Coat
•
Glycocalyx (cell coat)
• •
Surrounds cell Polysaccharides extend from plasma membrane
20
2/9/2011
ECM
•
Extracellular matrix (ECM)
• •
Surrounds many animal cell Carbohydrates and protein glycoproteins of ECM bind to integrins receptor proteins in plasma membrane
•
Fibronectins
• •
•
Integrins
•
ECM
Cell Wall
•
Cellulose & other polysaccharides
• •
form rigid cell walls in bacteria, fungi, and plant cells
21
Organization of the Cell
Chapter 4
Cell Theory
Cells are basic units of organization and function in all living organisms (2) All cells come from other cells
(1)
All living cells have evolved from a common ancestor
Learning Objective 2
•
What is the relationship between cell organization and homeostasis? homeostasis?
1
2/9/2011
Homeostasis
Cells have many organelles, internal organelles, structures that carry out specific functions, that help maintain homeostasis
•
KEY CONCEPTS
•
Cell organization and size are critical in maintaining homeostasis
Plasma Membrane
•
Plasma membrane
• • • •
surrounds the cell separates cell from external environment maintains internal conditions allows the cell to exchange materials with outer environment
2
2/9/2011
KEY CONCEPTS
Eukaryotic cells are divided into compartments by internal membranes • Membranes provide separate, small areas for specialized activities
•
Learning Objective 4
What methods do biologists use to study cells? • How are microscopy and cell fractionation used?
•
Microscopes
Light microscopes • Electron microscopes
•
•
superior resolving power
3
2/9/2011
Microscopes
Cell Fractionation
Cell fractionation
• •
•
purifies organelles to study function of cell structures
Cell Fractionation
4
2/9/2011
Learning Objective 5
•
How do the general characteristics of prokaryotic and eukaryotic cells differ? • How are plant and animal cells different?
Prokaryotes
•
Prokaryotic cells
• • • • •
No internal membrane organization nuclear area (not nucleus) cell wall ribosomes flagella
Prokaryotes
5
2/9/2011
Eukaryotes
•
Eukaryotic cells
• • •
membranemembrane-enclosed nucleus cytoplasm contains organelles cytosol (fluid component)
Chromatin Nucleolus Nuclear envelope Nuclear pores Nucleus Golgi complex Membranous sacs of Golgi
Plasma membrane Lysosome Nuclear envelope Cristae Ribosomes
Rough ER Rough and smooth endoplastic reticulum (ER) Smooth ER Centrioles Mitochondrion Fig. 4-8, p. 83
Plant Cells
•
Plant cells
• • • •
rigid cell walls Plastids i.e. chloroplasts & chromoplasts large vacuoles no centrioles
6
2/9/2011
Mitochondrion
Cristae Membranous sacs Golgi complex
Cell wall Plasma membrane Vacuole
Chloroplast Granum Stroma Rough ER Ribosomes Smooth ER
Nucleus
Nuclear envelope Nucleolus Nuclear pores Chromatin Rough and smooth endoplasmic reticulum (ER)
Fig. 4-7, p. 82
Learning Objective 6
•
What are the three functions of cell membranes? membranes?
Cell Membranes
Divide cell into compartments Vesicles transport materials between compartments • Important in energy storage and conversion • Endomembrane system
• •
7
2/9/2011
Learning Objective 7
What are the structures and functions of the nucleus? nucleus?
•
The Nucleus
•
Control center of cell
•
genetic information coded in DNA double membrane communicate with cytoplasm
•
Nuclear envelope
•
•
Nuclear pores
•
Nuclear Structures
•
Chromatin
•
DNA and protein DNA condensed for cell division ribosomal RNA synthesis ribosome assembly
•
Chromosomes
•
•
Nucleolus
• •
8
2/9/2011
The Nucleus
KEY CONCEPTS
•
Eukaryotic cells have nuclei containing genetic information coded in DNA
Learning Objective 8
•
What are the structural and functional differences between smooth ER and rough ER? ER?
9
2/9/2011
Endoplasmic Reticulum (ER)
•
Network of folded membranes
•
in cytosol lipid synthesis calcium ion storage detoxifying enzymes ribosomes on outer surface assembles proteins
•
Smooth ER
• • •
•
Rough ER
• •
ER
Learning Objective 9
•
Trace the path of protein synthesis:
• •
•
synthesis in the rough ER processing, modification, and sorting by the Golgi complex transportation to specific destinations
10
2/9/2011
The Golgi Complex
Processes proteins synthesized by ER • Manufactures lysosomes • Cisternae
•
•
stacks of flattened membranous sacs
Transport Vesicles
Formed by membrane budding • Move glycoproteins
•
• •
from ER to cis face of Golgi complex Carry modified proteins from trans face to specific destination
Polypeptides synthesized on ribosomes are inserted into ER lumen. Ribosomes Sugars are added, forming glycoproteins. Rough ER Transport vesicles Glycoprotein deliver glycoproteins to cis face of Golgi. Glycoproteins modified further in Golgi. Glycoproteins move to trans face where they are packaged in transport vesicles. Glycoproteins transported to plasma membrane (or other organelle). Contents of transport vesicle released from cell. Plasma membrane
cis face
trans face
Golgi complex
Fig. 4-14, p. 92
11
2/9/2011
KEY CONCEPTS
•
Proteins are
• • • •
synthesized on ribosomes processed in the endoplasmic reticulum processed by the Golgi complex transported by vesicles
Learning Objective 10
•
What are the functions of lysosomes, lysosomes, vacuoles, vacuoles, and peroxisomes? peroxisomes?
Other Organelles
•
Lysosomes
•
enzymes break down structures store materials in plant cells produce and degrade hydrogen peroxide (catalase) catalase)
•
Vacuoles
•
•
Peroxisomes
•
12
2/9/2011
Learning Objective 11
Compare the functions of mitochondria and chloroplasts • How is ATP synthesized by each of these organelles?
•
Mitochondria
•
Site of aerobic respiration • Double membrane
• •
inner membrane folded (cristae) (cristae) matrix (cristae and inner compartment) programmed cell death
•
Important in apoptosis
•
Outer mitochondrial membrane
Inner mitochondrial membrane
Matrix Cristae
0.25 µm Fig. 4-19, p. 95
13
2/9/2011
Aerobic Respiration
Breaks down nutrients using oxygen Energy from nutrients packaged in ATP • CO2, H2O produced as by-products by• •
Plastids
•
Plastids
• •
organelles that produce and store food in cells of plants and algae plastids that carry out photosynthesis
•
Chloroplasts
•
Chloroplast Structure
•
Stroma
•
fluidfluid-filled space enclosed by inner membrane of chloroplast stacks of membranous sacs (thylakoids) (thylakoids) suspended in stroma
•
Grana
• •
14
2/9/2011
Outer membrane
Inner membrane
Stroma
1 µm
Intermembrane Thylakoid space membrane Thylakoid lumen
Granum (stack of thylakoids)
Fig. 4-20, p. 96
Photosynthesis
•
Chlorophyll
• •
green pigment in thylakoid membranes traps light energy
•
Light energy converted to chemical energy in ATP
•
used to synthesize carbohydrates from carbon dioxide and water
Aerobic respiration Mitochondria (most eukaryotic cells)
Photosynthesis Chloroplasts (some plant and algal cells) Light
Glucose
Glucose
Fig. 4-18, p. 95
15
2/9/2011
KEY CONCEPTS
•
Mitochondria and chloroplasts convert energy from one form to another
Learning Objective 12
•
What are the structures and functions of the cytoskeleton? cytoskeleton?
The Cytoskeleton
• •
Microtubules
•
hollow tubulin cylinders actin filaments important in cell movement strengthen cytoskeleton stabilize cell shape
Microfilaments
• •
•
Intermediate filaments
• •
16
2/9/2011
Microtubules
Microfilaments
Intermediate Filaments
17
2/9/2011
Cytoskeleton
Centrosome
•
Usually contains two centrioles • Each centriole has 9 x 3 arrangement of microtubules
Centrioles
18
2/9/2011
KEY CONCEPTS
The cytoskeleton is a dynamic internal framework that functions in various types of cell movement
•
Learning Objective 13
•
How do cilia and flagella differ in structure and function?
Cilia and Flagella
•
Cilia and flagella
• • •
thin, movable structures project from cell surface function in movement
•
Cilia are short, flagella are long
19
2/9/2011
Cilia
Learning Objective14
•
Describe the glycocalyx, extracellular glycocalyx, matrix, matrix, and cell wall
Cell Coat
•
Glycocalyx (cell coat)
• •
Surrounds cell Polysaccharides extend from plasma membrane
20
2/9/2011
ECM
•
Extracellular matrix (ECM)
• •
Surrounds many animal cell Carbohydrates and protein glycoproteins of ECM bind to integrins receptor proteins in plasma membrane
•
Fibronectins
• •
•
Integrins
•
ECM
Cell Wall
•
Cellulose & other polysaccharides
• •
form rigid cell walls in bacteria, fungi, and plant cells
21
