Proteins are organic molecules consisting of many amino acids bonded together.
Amino Acids: Monomers or building blocks of all proteins.
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.
Peptide bonds: Bond formed when 2 amino acids bond by condensation synthesis (See diagram below.)
Dipeptide- 2 amino acids joined by peptide bond.
Polypeptide- many amino acids bonded together.
Functions of Proteins & Named Examples1) 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