2.6 Proteins

Question 1

Why are proteins important?

Answer 1

Proteins are the major structural materials of animal tissue and are also involved in the maintenance and regulation of life processes

Question 2

What is an enzyme?

Answer 2

Enzymes are proteins which act as biological catalysts

Question 3

What are amino acids?

Answer 3

Amino acids are the building blocks from which proteins are formed.
They re relatively small molecules which all contain an amino group, -NH2, and a carboxyl group, -COOH

Question 4

How are proteins made?

Answer 4

Proteins are made of many amino acid molecules linked together by condensation reactions. In these reactions, the amino group of one amino acid and the carboxyl group of another amino acid join, with the elimination of water

Question 5

The link which forms between two amino acids

Answer 5

Peptide/amide link, -CONH-

Question 6

How do proteins fulfil different roles in the body?

Answer 6

By linking together differing sequences of amino acids

Question 7

Amino acids which the body cannot make

Answer 7

Essential amino acid which must be acquired from the diet

Question 8

What happens during digestion?

Answer 8

During digestion, enzyme hydrolysis of protein produces amino acids

Question 9

How are proteins held in shape?

Answer 9

Long-chained protein molecules can form spirals, sheets or other complex shapes.
The chains are held in these forms by intermolecular bonding between the side chains of the constituent amino acids.
When proteins are heated, these intermolecular bonds are broken, allowing the proteins to change shape or denature.
The denaturing of proteins in foods causes the texture to change when it is cooked