Proteins

Question 1

Denaturation

Answer 1

Unfolding of a protein chain - irreversible change in shape

Question 2

Maillard reaction

Answer 2

Non-enzymic browning of food due to a reaction between certain amino acids and sugars under dry heat. Produces an attractive brown colour.
Eg. Potatoes

Question 3

Gel formation

Answer 3

Collagen converts to gelatine. Gelatine absorbs large amounts of water forming a sol. On cooling, sol forms a gel.
Eg. Cheesecake

Question 4

Foam formation

Answer 4

Egg white whisked, protein chains unfold and air bubbles form. Protein chains entrap air creating a foam. Whisking generates heat which sets egg albumin forming temporary foam. Will collapse if not heated to coagulate and set as permanent foam.
Eg. Meringues

Question 5

Functions of proteins

Answer 5

Growth and repairs of cells.
Production of cell membranes.
Production of antibodies.

Question 6

Deamination

Answer 6

Excess amino acids are brown down by body in liver.

Question 7

Essential amino acids

Answer 7

Cannot be manufactured by body and must be obtained from food.

Question 8

Non-essential amino acids

Answer 8

Can be manufactured by body and do not need to be obtained from food.