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www.denniskunkel.com
www.denniskunkel.com
Tour of the Cell Today’s Topics • Properties of all cells • Prokaryotes and Eukaryotes • Functions of Major Cellular
Organelles – Information
• Nucleus, Ribosomes – Synthesis&Transport
• ER, Golgi, Vesicles – Energy Conversion
• Mitochondria, Chloroplasts – Recycling
• Lysosome, Peroxisome – Structure and Movement
• Cytoskeleton and Motor Proteins
• Cell Walls
9/16/11
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Common features of all cells • Plasma Membrane
– defines inside from outside
• Cytosol – Semifluid “inside” of the cell
• DNA “chromosomes” - Genetic material – hereditary
instructions
• Ribosomes – “factories” to synthesize proteins
4
Bacterial (Prokaryotic) Cell
Ribosomes!
Plasma membrane!
Cell wall!
Flagella!
Bacterial chromosome!
0.5 !m!
No internal membranes
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Contains internal organelles
Eukaryotic Cell Figure 6.2b
1 mm
100 µm
10 µm
1 µm
100 nm
10 nm
1 nm
0.1 nm Atoms
Small molecules
Lipids Proteins
Ribosomes
Viruses Smallest bacteria
Mitochondrion Most bacteria Nucleus
Most plant and animal cells
Human egg
Ligh
t mic
rosc
opy
Elec
tron
mic
rosc
opy
Super- resolution
microscopy
1 cm
Frog egg
2
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Rough ER Smooth ER
Centrosome
CYTOSKELETON
Microfilaments
Microtubules
Peroxisome
Lysosome
Golgi apparatus
Ribosomes
In animal cells but not plant cells: Lysosomes Centrioles Flagella (in some plant sperm)
NUCLEUS
Intermediate filaments
ENDOPLASMIC RETICULUM (ER)
Mitochondrion
Plasma membrane
Figure 6.9
endoplasmic reticulum nucleus
mitochondrion lysosome
Golgi apparatus cytosol
ribosomes
cytoskeleton You should know everything in Fig 6.9
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Rough ER Smooth ER
Centrosome
CYTOSKELETON
Microfilaments
Microtubules
Peroxisome
Lysosome
Golgi apparatus
Ribosomes
In animal cells but not plant cells: Lysosomes Centrioles Flagella (in some plant sperm)
NUCLEUS
Intermediate filaments
ENDOPLASMIC RETICULUM (ER)
Mitochondrion
Plasma membrane
Figure 6.9
Nucleus
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Nuclear envelope
Figure 6.10
Nucleus
Nucleus Nucleolus
Chromatin
Nuclear envelope: Inner membrane
Outer membrane
Pores
Rough ER
Pore complex
Surface of nuclear envelope.
Pore complexes (TEM). Nuclear lamina (TEM).
Close-up of nuclear envelope
Ribosome
1 !m
1 !m
0.25 !m
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– Carry out protein synthesis ER
Cytosol Free Ribosomes
Membrane Bound Ribosomes
Large subunit
Small subunit
TEM showing ER and ribosomes
Diagram of a ribosome
0.5 !m
Figure 6.11 RNA & Protein Complex
Make Proteins to be Exported
Make Cytoplasmic Proteins
Ribosomes
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Rough ER Smooth ER
Centrosome
CYTOSKELETON
Microfilaments
Microtubules
Peroxisome
Lysosome
Golgi apparatus
Ribosomes
In animal cells but not plant cells: Lysosomes Centrioles Flagella (in some plant sperm)
NUCLEUS
Intermediate filaments
ENDOPLASMIC RETICULUM (ER)
Mitochondrion
Plasma membrane
Figure 6.9
Endoplasmic Reticulum
Golgi apparatus
Ribosomes
12 4 5 6
Nuclear envelope is connected to ER
Nucleus
Rough ER Smooth ER
Golgi
transport vesicles
Golgi pinches off Transport Vesicles, Lysosomes, etc.
1
3
2
Figure 6.16 Plasma membrane expands by fusion of vesicles.
3
13
Smooth ER
• Synthesis of membrane lipids
• Synthesizes steroids • Stores calcium • Detoxifies poison
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Rough ER
• Synthesis of – secreted proteins – membrane proteins
Has attached ribosomes
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Adds oligosaccharides (glycosylation)
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Cis Golgi
Close To Rough
ER
Trans Golgi
Away From
Rough ER
Golgi Apparatus: protein secretion Processing, packaging and sorting center
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NUCLEUS
Figure 6.9
Mitochondria (and chloroplasts)
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Mitochondria: Powerhouses of the cell
Food -> ATP
4
19
Chloroplast
Chloroplast DNA
Ribosomes
Stroma
Inner and outer membranes
Thylakoid
1 !m
Granum
Chloroplasts capture energy from the sun
Photosynthesis
Sunlight -> ATP, Sugar 20
Rough ER Smooth ER
Lysosome
ENDOPLASMIC RETICULUM (ER)
Figure 6.9 Lysosome (animals only)
Peroxisome
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Rough ER Smooth ER
CYTOSKELETON
Microfilaments
Microtubules
NUCLEUS
Intermediate filaments
ENDOPLASMIC RETICULUM (ER)
Figure 6.9
Cytosol
Cytoskeleton
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There are three types of
fibers that make up the cytoskeleton
Table 6.1
Microtubules Microfilaments Intermediate Filaments
Tubulin 25 mM dia
Actin 7 mM dia various
8-15 mM dia
Cell shape Organelle movt Chromosome separation Flagellar mvt
Cell shape Cell cleavage Cytoplasmic streaming Muscle contract
Nuclear lamina Tension bearing elements Anchors
Motors: Dynein Kinesin
Motors: Myosin
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Movement of Vesicles along Microtubules
Vesicle ATP
Receptor for motor protein
Motor protein (ATP powered)
Microtubule of cytoskeleton
(a) Motor proteins that attach to receptors on organelles can “walk” the organelles along microtubules or, in some cases, microfilaments.
Microtubule Vesicles 0.25 !m
(b) Vesicles containing neurotransmitters migrate to the tips of nerve cell axons via the mechanism in (a). In this SEM of a squid giant axon, two vesicles can be seen moving along a microtubule. (A separate part of the experiment provided the evidence that they were in fact moving.) Figure 6.21 A, B
What evidence do we have that they actually move?
24
5
25
Three kinds of Movement
• Filament anchored: motor “walks” along filament (transport vesicles)
• Motor anchored: filament moves (muscles)
• Both anchored: bending (cilia and flagella)
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Motor MAPs transport vesicles
MTOC
Dynein inbound
outbound kinesin
27
Fig. 6-24
0.1 !m!Triplet!
(c) Cross section of basal body!
(a)!Longitudinal section of cilium!
0.5 !m!
Plasma membrane!
Basal body!
Microtubules!
(b)!Cross section of cilium!
Plasma membrane!
Outer microtubule doublet!Dynein proteins!
Central microtubules!
0.1 !m!
Cilia and Flagella Have 9+2 arrangement of microtubules and motor proteins.
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CYTOSKELETON
Ribosomes (small brown dots)
Central vacuole/Tonoplast
Microfilaments Intermediate filaments
Microtubules
Rough endoplasmic reticulum
Smooth endoplasmic reticulum
NUCLEUS
Chloroplast
Plasmodesmata Wall of adjacent cell
Cell wall
Golgi apparatus
Peroxisome Plasma membrane
Mitochondrion
Figure 6.9
Plants have 2 other support mechanisms
• Cell Wall • Vacuole or
Tonoplast
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Central Vacuoles (Tonoplasts) – Only in plants
Central vacuole
Cytosol
Tonoplast
Central vacuole
Nucleus
Cell wall
Chloroplast
5 !m
Figure 6.15
Acts like a “balloon in a box” to hold plant cells rigid
30
Extra Cellular Matrix
glycoproteins