1. Cell Biology Overview A. Types of Cells 1. Prokaryotic Cells
(eubacteria and archaea)
- no nucleus
- no organelles
- binary fission
- small (0.2 – 2.0 um)

2. Cell Biology Overview A. Types of Cells 1. Prokaryotic Cells
Staphyloccocus aureus biofilm
Cell Biology
Overview
A. Types of Cells
1. Prokaryotic Cells
- biofilms

3. Cell Biology Overview A. Types of Cells 1. Prokaryotic Cells
2. Eukaryotic Cells
(protists, plants,
fungi, animals)
- nucleus
- organelles
- mitosis
- larger ( um)

4. Cell Biology Overview A. Types of Cells 1. Prokaryotic Cells
2. Eukaryotic Cells
B. How Cells Live
- take stuff in

5. Cell Biology Overview A. Types of Cells 1. Prokaryotic Cells
2. Eukaryotic Cells
B. How Cells Live
- take stuff in
- break it down and
harvest energy
(enzymes needed)
mitochondria
ADP +P
ATP

6. Cell Biology Overview A. Types of Cells 1. Prokaryotic Cells
2. Eukaryotic Cells
B. How Cells Live
- take stuff in
- break it down and
harvest energy
(enzymes needed)
and
- transform radiant energy
to chemical energy
ADP +P
ATP
chloroplast
mitochondria
ADP +P
ATP

7. Cell Biology Overview A. Types of Cells 1. Prokaryotic Cells
2. Eukaryotic Cells
B. How Cells Live
- take stuff in
- break it down and
harvest energy
(enzymes needed)
- use energy to make stuff
(like enzymes and other proteins,
and lipids, polysaccharides, and
nucleic acids)
- DNA determines sequence of amino acids in enzymes and other proteins
ADP +P
ATP
ribosome

8. ADP +P
ATP
ribosome

9. C. Why are cells small?
Bigger is better….

10. C. Why are cells small?
Bigger is better….
So selection favors growth…
But as cells increase in size, they decrease in efficiency.

11. SA/V = 6
SA/V = 3
SA/V = 1.5
The “surface area to volume ratio” decreases as something increases in size….

12. SA/V = 6
SA/V = 3
SA/V = 1.5
The “surface area to volume ratio” decreases as something increases in size….
The surface area – the membrane – limits the rate of supply of nutrients to the cell.
The volume – where all the enzymes are – represents potential production and ‘demand’ for nutrients.

13. SA/V = 6
SA/V = 3
SA/V = 1.5
So, as something gets larger, the volume increases more than the surface area… and the demand for nutrients (to meet peak productivity) grows faster than the rate at which the more slowly increasing SA can supply them. So, supply fails to meet demand, and the cell cannot meet peak productivity… it becomes less efficient.

14. Biologically Important Molecules
Water
Carbohydrates

15. Carbohydrates
A. Structure
1. monomer = monosaccharide
typically 3-6 carbons, and CnH2nOn formula

16. Carbohydrates
A. Structure
1. monomer = monosaccharide
2. polymerization:
dehydration synthesis reaction

17. Carbohydrates
A. Structure
1. monomer = monosaccharide
2. polymerization
3. Polymers = polysaccharides

18. Disaccharides

19. Polysaccharides

20. Polysaccharides

21. Polysaccharides
The ‘cross-linkages’ in cellulose are not digestible by starch-digesting enzymes, so animals cannot eat wood unless they have bacterial endosymbionts. Decomposing fungi and bacteria also have these enzymes, and can access the huge amount of energy in cellulose.

22. Polysaccharides
glucosamine

23. - energy storage (short and long) - structural (cellulose and chitin)
Carbohydrates
A. Structure
B. Function
- energy storage (short and long)
- structural (cellulose and chitin)
CO2
Glucose, Cellulose,
Starch
H2O

24. Biologically Important Molecules
Water
Carbohydrates
Lipids

25. III. Lipids
- not true polymers or macromolecules; an assortment of hydrophobic, hydrocarbon molecules classes as fats, phospholipids, waxes, or steroids.

26. III. Lipids
A. Fats
- structure
glycerol (alcohol) with three fatty acids

27. (or triglyceride)

28. -saturated fats (no double bonds)
III. Lipids
A. Fats
- structure
-saturated fats (no double bonds)
Straight chains pack tightly; solid at room temperature like butter and lard.
Implicated in plaque build-up in blood vessels (atherosclerosis)
Animal fats (not fish oils)

29. -unsaturated fats (no double bonds)
III. Lipids
A. Fats
- structure
-unsaturated fats (no double bonds)
Plant and fish oils
Kinked; don’t pack – liquid at room temperature.
“Hydrogenation” can make them saturated and solid, but the process also produces trans-fats (trans conformation around double bond) which may contribute MORE to atherosclerosis than saturated fats)

30. - long term energy storage (dense)
III. Lipids
A. Fats
- structure
- functions
- long term energy storage (dense)
not vital in immobile organisms (mature plants), so it is metabolically easier to store energy as starch. But in seeds and animals (mobile), there is selective value to packing energy efficiently, in a small space.
In animals, fat is stored in adipose cells

31. - long term energy storage (dense) - insulation (subcutaneous fat)
III. Lipids
A. Fats
- structure
- functions
- long term energy storage (dense)
- insulation (subcutaneous fat)
- cushioning

32. III. Lipids A. Fats B. Phospholipids - structure Glycerol
2 fatty acids
phosphate group (and choline)
Hydrophilic and hydrophobic regions

33. III. Lipids A. Fats B. Phospholipids - function selective membranes
In water, they spontaneously assemble into micelles or bilayered liposomes.

34. Biologically Important Molecules
Water
Carbohydrates
Lipids
Proteins

35. Proteins A. structure - monomer: amino acids Carboxyl group
Amine group

36. Proteins A. structure - monomer: amino acids
20 AA’s found in proteins, with different chemical properties. Of note is cysteine, which can form covalent bonds to other cysteines through a disulfide linkage.

37. - polymerization: dehydration synthesis
Proteins
A. structure
- monomer: amino acids
- polymerization: dehydration synthesis
The bond that is formed is called a peptide bond

38. - polymerization: dehydration synthesis - polymer: polypeptide
Proteins
A. structure
- monomer: amino acids
- polymerization: dehydration synthesis
- polymer: polypeptide
May be 1000’s of aa’s long
Not necessarily functional (“proteins” are functional polypeptides)
Sequence determines the function

40. Actin filament in muscle is a sequence of globular actin proteins…

41. 50 myofibrils/fiber (cell)

42. Proteins
A. structure
B. functions!
- catalysts (enzymes)
- structural (actin/collagen/etc.)
- transport (hemoglobin, cell membrane)
- immunity (antibodies)
- cell signaling (surface antigens)

43. Proteins A. structure B. functions! C. designer molecules
If protein function is ultimately determined by AA sequence, why can’t we sequence a protein and then synthesize it?

44. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
1. phospholipids

45. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
2. proteins and carbohydrates

46. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
Aqueous Solution (outside cell)
dissolved ions
dissolved polar molecules
suspended non-polar
(lipid soluble)
Aqueous Solution (inside cell)
dissolved ions
dissolved polar molecules
suspended non-polar
(lipid soluble)

47. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
2. transport
Net diffusion
Net diffusion
equilibrium

48. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
2. transport - diffusion
Net diffusion
Equilibrium
Net diffusion
Net diffusion
equilibrium

49. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
2. transport - osmosis

50. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
2. transport – facilitated diffusion

51. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
2. transport – active transport

52. Cytoplasmic Na+ bonds to
the sodium-potassium pump
Na+ binding stimulates
phosphorylation by ATP.
Phosphorylation causes
the protein to change its
conformation, expelling Na+
to the outside.
Extracellular K+ binds
to the protein, triggering
release of the phosphate
group.
Loss of the phosphate
restores the protein’s
original conformation.
K+ is released and Na+
sites are receptive again;
the cycle repeats.

53. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
2. transport
3. metabolism (enzymes nested in membrane)
4. signal transduction

54. Cell Biology
Overview
II. Membranes – How Things Get in and Out of Cells
A. Membrane Structure
B. Membrane Function
1. semi-permeable barrier
2. transport
3. metabolism (enzymes nested in membrane)
4. signal transduction
5. cell-cell binding
6. cell recognition
7. cytoskeleton attachment