1. Protein
Functions of Proteins

2. The word 'protein' is derived from a Greek word 'protas' meaning 'of primary importance.‘
High consumption of protein (meat) is a symbol of civilization itself (Max Rubner )

3. kwashiorkor

4. What are proteins
Protein Bozeman

5. Proteins are polymers of amino acids chemically bonded to each other
All proteins in humans are made up from 20 different amino acids
Identification: many protein names end with –in, -en, -ase

6. Also Keratin for hair and nails
Types of Proteins
1. Structural – collagen
Also Keratin for hair and nails

7. 2. Contractile Proteins
Actin/Myosin in muscles) Provide movement muscle contraction

8. 3. Transport Protein
Cross Membrane Transport membrane crossing Oxygen Transport: Hemoglobin

9. 4. Storage proteins
Example: Casein amino acid storage in mammalian milk (80% cow’s, 30% human milk)

10. 5. Protein Hormones
Example: Insulin and Glucagon (blood sugar regulation)

11. 6. Enzymes
Speed up reactions in the body Example: Lactase breaks down Lactose into Galactose and Glucose How Enzymes work

12. 7. Immune Proteins
Defend body against pathogens Example: Antibodies Antibody function

13. Table 16.1 – page 534

14. Chapter 16.2
Amino Acids
SWBAT: know the structure of an amino acid and be familiar with the classification of amino acids

15. Anatomy of an Amino Acid
AA are all the same with regard to 1. Central carbon 2. Amino group 3. Carboxyl group 4. Extra Hydrogen Differ with regard to the R-side chain

16. Acid/Base behavior of functional groups
At normal body pH (~7.4) the amino and carboxyl group exist in their charged version
NH3+
COO-
amines are bases:
accept a proton H+
carboxylic acids are acids: release a proton H+
Called a Zwitterion: positively and negatively charged at the same time!!!

17. Side Chain (R) Group can be: Alkyl Hydroxyl Thiol Amino Carboxyl
Amino Acid (R) Group
Side Chain (R) Group can be:
Alkyl
Hydroxyl
Thiol
Amino
Carboxyl
Aromatic
Cyclical
Amide

18. Classification of Amino Acids
Polar
Amino Acid
Non-polar
Neutral
(not charged)
Positively charged
(Basic)
Charged
Negatively charged
(Acidic)

19. Nonpolar Amino Acids
R can be:
Alkyl side chain
Aromatic side chain

20. These can H-bond with water
Polar Amino Acids
R can be:
Hydroxyl (-OH)
Thiol (-SH)
Amide (-CONH2)
These can H-bond with water

21. Can ionize as a weak acid
Acidic Amino Acids
R will be:
Carboxylic acid (-COOH)
Can ionize as a weak acid

22. an amino group that ionizes as a weak base
Basic Amino Acids
R group will contain:
an amino group that ionizes as a weak base

23. Amino Acid Stereoisomers
Amino acids (except Glycine) are chiral – can exist as D or L enantiomers
Fisher projections:
Highest oxidized C on top: COOH
R side chain at bottom
L - isomer – NH2 group on left
D - isomer – NH2 group on right
L-serine
D-serine
Only L-amino acids found in nature!