1. Biologically Important Molecules
Glycine (AA)

2. I. Water A. Structure – did it B. Properties Solvent
High specific heat (thermally stable)
High heat of vaporization
Adhesive/cohesive

3. I. Water
C. Water and Life
Life on Earth is inconceivable without water.
Life requires rapid and continuous chemical reactions facilitated by a dissolution of reactants in a liquid solvent.
Water’s solvent properties are ideal.
Water is a liquid over a wide temperature range that is very common on Earth. (High specific heat, vaporization).
Water is abundant on Earth, covering over 70% of the surface.
Water is a thermally stable internal/external environment.
No surprize that life probably originated in water (3.8 bya), and did not adapt to exploit the desiccating terrestrial environments until the last ~10% of Life’s history (0.4 bya).

4. Biologically Important Molecules
Water
Carbohydrates

5. 1. monomer = monosaccharide typically 3-6 carbons, and CnH2nOn formula
Carbohydrates
A. Structure
1. monomer = monosaccharide
typically 3-6 carbons, and CnH2nOn formula
have carbonyl and hydroxyl groups
carbonyl is either ketone or aldehyde
in aqueous solutions, they form rings

6. Carbohydrates
A. Structure
1. monomer = monosaccharide
2. polymerization form polysaccharides
dehydration synthesis reaction

7. Disaccharides

8. Polysaccharides

9. Polysaccharides

10. Polysaccharides
glucosamine

11. - 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

12. Biologically Important Molecules
Water
Carbohydrates
Lipids

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

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

15. (or triglyceride)

16. -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)

17. -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)

18. - 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

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

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

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

22. III. Lipids A. Fats B. Phospholipids C. Waxes - structure
An alcohol and fatty acid
 Wax
 Alcohol
 Fatty Acid
 Carnuba
CH3(CH2)28CH2-OH
CH3(CH2)24COOH
 Beeswax
 CH3(CH2)14COOH
 Spermacetic
CH3(CH2)14CH2-OH
CH3(CH2)14COOH

23. III. Lipids A. Fats B. Phospholipids C. Waxes - structure - function
Retard the flow of water (plant waxes)
Structural (beeswax in honeycomb)
Signals – waxes on the exoskeleton can signal an insect’s identity and sexual receptivity.

24. typically a four-ring structure with side groups
III. Lipids
A. Fats
B. Phospholipids
C. Waxes
D. Steroids
- structure
typically a four-ring structure with side groups
cholesterol and its hormone derivatives

25. Cholesterol

26. Biologically Important Molecules
Water
Carbohydrates
Lipids
Proteins

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

28. 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.

29. - polymerization forms polypeptides/proteins
A. structure
- monomer: amino acids
- polymerization forms polypeptides/proteins
The bond that is formed is called a peptide bond

30. Proteins
A. structure
- monomer: amino acids
- polymerizationforms polypeptide/protein
- protein has 4 levels of structure
1o (primary) = AA sequence
2o (secondary) = pleated sheet or helix
3o (tertiary) = folded into a glob
4o (quaternary) = >1 polypeptide

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

33. 50 myofibrils/fiber (cell)

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

35. 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?
Folding is critical to function, and this is difficult to predict because it is often catalyzed by other molecules called chaparones
By analyzing large numbers of protein sequences and structures, correlations between “functional motifs” and particular sequences are resolved.