PROTEINS

Question 1

Function: Mechanical support.
Example: Collagen, found in all connective tissue, is the single most abundant protein in the body. It is responsible for the tensile strength of bones, tendons, and ligaments.

Answer 1

Structural proteins

Question 2

Function: Catalysis. Protein enzymes are essential for virtually every biochemical reaction in the body. Examples: Disaccharidases hydrolyze disaccharides, proteases hydrolyze proteins, and oxidases oxidize food fuels.

Answer 2

Enzyme proteins

Question 3

Function: Moving substances (in blood or across plasma membranes). Example: Hemoglobin transports oxygen in blood. Some plasma membrane proteins transport substances (such as ions) across the plasma membrane.

Answer 3

Transport proteins

Question 4

Function: Movement.
Example: Actin and myosin cause muscle cell contraction and function in cell division in all cell types

Answer 4

Contractile proteins

Question 5

Function: Transmitting signals between cells. Can act as chemical messengers (e.g., hormones) or as receptors in the plasma membrane. Example: Insulin (a protein) acts at its receptor to regulate blood sugar levels.

Answer 5

Communication proteins

Question 6

Function: Protect against disease. Example: Antibodies released by certain immune cells are specialized proteins that bind and inactivate foreign substances (e.g., bacteria, toxins, viruses).

Answer 6

Defensive proteins