Vitamin required for collagen synthesis -

Ans. is 'b' i.e., Vitamin C o Ascorbic acid functions as a reducing agentQ and scavanger of free radicals (antioxidant) Q. Its major functions are:-In collagen synthesis : - Vitamin C is required for post-translational modificationQ by hydroxylation of proline and lysineQ residues converting them into hydroxyprolineQ and hydroxylysine. Thus vitamin C is essential for the conversion of procollagen to collagen, which is rich in hydroxyproline and hydroxylysine. Through collagen synthesis, it plays a role in formation of matrix of bone, cartilage, dentine and connective tissue.Synthesis of norepinephrine from dopamine by dopamine-b-monoxygenase (dopamine-b-hydroxylase ) requires Vitamin C.Carnitine synthesisBile acid synthesis :- 7-a-hydroxylase requires vitamin C.Absorption of iron is stimulated by ascorbic acid by conversion of ferric to ferrous ions.During adrenal steroid synthesis, ascorbic acid is required during hydroxylation reactions.Tyrosine metabolism : - Oxidation of P-hydroxy-phenylpyruvate to homogentisate.Folate metabolism : - Folic acid is converted to its active form tetrahvdrofolate by help of Vitamin C.