Lecture 20b

1
Lecture 20b
Cells 2
2
Animal Cell
Nucleus
Smooth Endoplasmic Reticulum
Ribosomes
Lysosome
Rough Endoplasmic Reticulum
Golgi apparatus
Centrioles
Plasma membrane
Mitochondrion
3
Plant Cell
4
Plasma Membrane
5
Membrane Functions
Enclose cell Surround organelles Provide
attachment sites Cell-cell recognition
6
Membrane Size Structure
Keeps things in/out Large area more regulatory
control Permits compartments Passing membrane may
be important
7
Compartments
Isolate materials Concentrate materials Allow
concentration gradients
Diffusion
membrane
8
Membrane Structure
Lipid bilayer Highly motile Life measured in
hours Embedded proteins Life measured in days
9
Membrane Structure
3D structure
10
Endocytosis
11
Exocytosis
12
Other Organelles
mitochondrion
chloroplast
13
Mitochondria Chloroplasts
Both are membrane bounded Both are relatively
large (bacterial size) Endosymbiotic
Hypothesis Mutualistic relationship between
different organisms True?
14
Mitochondrion
Very prominent Most cells have hundreds(plural
mitochondria) Powerhouse of the cell (fuel
molecules to ATP)
15
Mitochondrion
Metabolism Glucose (a sugar) to ATP ATP
universal energy currency
ADP energy ATP
16
concentration gradient
17
Chloroplast
Site of photosynthesis Similar to
mitochondrion Even larger Produces organic
compounds(these store energy)
18
Cytoskeleton
19
Cytoplasm Cytoskeleton
microfibersmicrotubules
20
Cytoplasm Cytoskeleton
Cytoplasm 1/2 cell volume Not simple gel-like
stuff Cytoskeleton gives shape Very
dynamic Sites of attachment 90 of proteins
Water
21
Animal
Vacuole Functions

• Storage
• Support
• Water Regulation

vacuole
Plant
mitochondria
chloroplasts
Both cell types havemembrane-bounded organelles
22
Endosymbiosis Hypothesis
A
A prokaryote ingested some aerobic bacteria. The
aerobes were protected and produced energy for
the prokaryote
A
B
C
D
Cyanobacteria
Aerobic bacteria
Chloroplasts
Mitochondria
N
N
Plant cell
Prokaryote
N
Animal Cell
23
Endosymbiosis Hypothesis
B
Over a long period of time the aerobes became
mitochondria, no longer able to live on their own
A
B
C
D
Cyanobacteria
Aerobic bacteria
Chloroplasts
Mitochondria
N
N
Plant cell
Prokaryote
N
Animal Cell
24
Endosymbiosis Hypothesis
C
Some primitive prokaryotes also ingested
cyanobacteria, which contain photosynthetic
pigments
A
B
C
D
Cyanobacteria
Aerobic bacteria
Chloroplasts
Mitochondria
N
N
Plant cell
Prokaryote
N
Animal Cell
25
Endosymbiosis Hypothesis
D
Cyanobacteria became chloroplasts, unable to live
on their own
A
B
C
D
Cyanobacteria
Aerobic bacteria
Chloroplasts
Mitochondria
N
N
Plant cell
Prokaryote
N
Animal Cell