$5.$ Scurvy is a disease resulting from a lack of vitamin C $($ascorbic acid$).$ People with scurvy suffer from loose teeth, delayed wound healing, sore arms and legs which are found to be associated with defects in collagen structure.

a$)$ Why vitamin C is required for the correct conformation of collagen? $(5$ pts$)$

b$)$ What are the contributions of hydroxyprolines and hydroxylysines to the native conformation of collagen? $(5$ pts$)$