Proteins are organic molecules consisting of many amino acids bonded together.

Amino Acids: Monomers or building blocks of all proteins.

The basic structure of a generalized amino acid is shown above. (Memorize this!)

Parts of the Amino Acid:

a) Amino group (NH2)

b) Carboxyl group (COOH)

c) R-group: variable- 20 R-groups, so only 20 amino acids.

Know how to draw this and label where the peptide bond is (See blue arrow).

[Another Protein Synthesis Diagram]

Dipeptide- 2 amino acids joined by peptide bond.

Polypeptide- many amino acids bonded together.

1) Enzyme catalysis: Enzymes help reactions occur more easily. Example- Amylase (Converts starch to simple sugar.)

2) Defense: Antibodies - Globular proteins that "recognize" foreign microbes.

3) Transport- Hemoglobin (red blood cell protein).

4) Structure / Support- Collagen, which forms the matrix of skin, ligaments, tendons and bones.

5) Motion- Actin, a muscle protein responsible for muscle contraction.

6) Regulation- Hormones which serve as intercellular messengers. Example - Insulin (blood sugar regulation).

Denaturation: protein shape altered with changes in pH, temperature. Change in shape alters activity of enzyme. Enzymes function within a narrow range of these factors.

[Carbohydrates] [Lipids] [Nucleic Acids]