1. Your Homework
Review the following slides and record information that is unfamiliar to you as well as questions you have.
The expectation is that you have learned Biomolecules in Biology and read chapter 2. We will not be spending a lot of time in class on this topic.

2. You Must Know The role of dehydration synthesis and hydrolysis
How to recognize the 4 organic compounds (carbs, lipids, proteins, nucleic acids) by structural formulas.
The cellular functions of all four organic compounds.
The 4 structural levels of proteins
Protein denaturing and range of activity of enzymes

3. Dehydration Synthesis (Condensation Reaction)
Hydrolysis
Make polymers
Breakdown polymers
Monomers  Polymers
Polymers  Monomers
A + B  AB
AB  A + B
+ H2O +
+ H2O +

5. Categories, functions and examples
Biomolecule type
Monomers
Categories, functions and examples
Carbohydrates
Proteins
Nucleic Acids
Lipids

6. Carbohydrates Energy and Structure Monomers –
CH2O (ratio of 1C:2H:1O)
Monomers –
C6H12O6 (monosaccharides) - used as energy source
(glucose, fructose, galactose)
Dimers –
C12H22O11 (disaccharides) – also energy source
(sucrose, lactose, maltose)
Polymers –
CH2O taken many times = Cn(H20)(n-1) – these are storage and structural

7. Carbohydrates Monosaccharides = monomers (eg. glucose, ribose)
Polysaccharides:
Storage (plants-starch, animals-glycogen)
Structure (plant-cellulose, arthropod-chitin)

8. The structure and classification of some monosaccharides

9. Linear and ring forms of glucose

10. Carbohydrate synthesis

11. Cellulose vs. Starch
Two Forms of Glucose:  glucose &  glucose

12. Cellulose vs. Starch Starch =  glucose monomers
Cellulose =  glucose monomers

13. Storage polysaccharides of plants (starch) and animals (glycogen)

14. Structural polysaccharides: cellulose & chitin (exoskeleton)

15. Proteins “Proteios” = first or primary 50% dry weight of cells
Contains: C, H, O, N, S
Myoglobin protein

16. Protein Functions (+ examples)
Enzymes (lactase)
Defense (antibodies)
Storage (milk protein = casein)
Transport (hemoglobin)
Hormones (insulin)
Receptors
Movement (motor proteins)
Structure (keratin)

17. Overview of protein functions

18. Overview of protein functions

19. Four Levels of Protein Structure
Primary
Amino acid (AA) sequence
20 different AA’s
peptide bonds link AA’s

20. Amino Acid R group = side chains “amino” : -NH2 “acid” : -COOH
Properties:
hydrophobic
hydrophilic
ionic (acids & bases)
“amino” : -NH2
“acid” : -COOH

23. Four Levels of Protein Structure (continued)
Secondary
Gains 3-D shape (folds, coils) by H-bonding
Alpha (α) helix, Beta (β) pleated sheet

24. Basic Principles of Protein Folding
Hydrophobic AA buried in interior of protein (hydrophobic interactions)
Hydrophilic AA exposed on surface of protein (hydrogen bonds)
Acidic + Basic AA form salt bridges (ionic bonds).
Cysteines can form disulfide bonds.

25. Four Levels of Protein Structure (continued)
Tertiary
Bonding between side chains (R groups) of amino acids
H bonds, ionic bonds, disulfide bridges, van der Waals interactions

26. Four Levels of Protein Structure (continued)
Quaternary
2+ polypeptides bond together

27. amino acids  polypeptides  protein
Bonding (ionic & H) can create asymmetrical attractions

28. Chaperonins assist in proper folding of proteins

29. Protein structure and function are sensitive to chemical and physical conditions
Unfolds or denatures if pH and temperature are not optimal

30. change in structure = change in function

31. Function: store hereditary info
II. Nucleic Acids
Function: store hereditary info
DNA
RNA
Double-stranded helix
N-bases: A, G, C, Thymine
Stores hereditary info
Longer/larger
Sugar: deoxyribose
Single-stranded
N-bases: A, G, C, Uracil
Carry info from DNA to ribosomes
tRNA, rRNA, mRNA, RNAi
Sugar: ribose

32. Nucleotides: monomer of DNA/RNA
Nucleotide = Sugar + Phosphate + Nitrogen Base

33. Nucleotide phosphate A – T Nitrogen G – C base 5-C sugar Purines
Pyrimidines
Adenine
Guanine
Cytosine
Thymine (DNA)
Uracil (RNA)
Double ring
Single ring
5-C sugar

35. Information flow in a cell: DNA  RNA  protein

36. II. Lipids Fats (triglyceride): store energy
Glycerol + 3 Fatty Acids
saturated, unsaturated, polyunsaturated
Steroids: cholesterol and hormones
Phospholipids: lipid bilayer of cell membrane
hydrophilic head, hydrophobic tails
Hydrophilic head
Hydrophobic tail

38. Have some C=C, result in kinks
Saturated
Unsaturated
Polyunsaturated
“saturated” with H
Have some C=C, result in kinks
In animals
In plants
Solid at room temp.
Liquid at room temp.
Eg. butter, lard
Eg. corn oil, olive oil

39. Cholesterol, a steroid

40. The structure of a phospholipid

41. Hydrophobic/hydrophilic interactions make a phospholipid bilayer

43. Wednesday’s Lecture Starts Here

44. Catalyst: substance that can change the rate of a reaction without being altered in the process
Enzyme = biological catalyst
Speeds up metabolic reactions by lowering the activation energy (energy needed to start reaction)

46. SUBSTRATE SPECIFICITY OF ENZYMES
The reactant that an enzyme acts on is called the enzyme’s substrate
The enzyme binds to its substrate, forming an enzyme-substrate complex
The active site is the region on the enzyme where the substrate binds

50. INDUCED FIT: ENZYME FITS SNUGLY AROUND SUBSTRATE -- “CLASPING HANDSHAKE”

51. An enzyme’s activity can be affected by:
temperature pH
chemicals

52. COFACTORS
Cofactors are nonprotein enzyme helpers such as minerals (eg. Zn, Fe, Cu)
Coenzymes are organic cofactors (eg. vitamins)
Enzyme Inhibitors
Competitive inhibitor: binds to the active site of an enzyme, competes with substrate
Noncompetitive inhibitor: binds to another part of an enzyme  enzyme changes shape  active site is nonfunctional

53. INHIBITION OF ENZYME ACTIVITY

54. REGULATION OF ENZYME ACTIVITY
To regulate metabolic pathways, the cell switches on/off the genes that encode specific enzymes
Allosteric regulation: protein’s function at one site is affected by binding of a regulatory molecule to a separate site (allosteric site)
Activator – stabilizes active site
Inhibitor – stabilizes inactive form
Cooperativity – one substrate triggers shape change in other active sites  increase catalytic activity