erm

Question 1

Explain why collagen is described as a fibrous protein [2]

Answer 1

1. Insoluble in water as the hydrophobic amino acids face the exterior of collagen
2. 3 helical polypeptide chain wound into a triple helix to form fibrils which in turn form long fibres

Question 2

Suggest with a reason whether Hb is a globular or fibrous protein [2]

Answer 2

Globular.

1. Soluble in aqueous medium/blood due to hydrophilic R groups facing the exterior, allowing it to perform its function of transporting oxygen through the blood
2. Repeated folding and coiling of polypeptide chain forms tertiary structure with a spherical shape