This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
[{'content': 'Vitamin C is necessary in the formation of collagen. It is required for the conversion of: \nSelect and explain. \nA. Proline to hydroxyproline, B. Beta-carotene to vitamin A, C. Glutamate to gamma-carboxyglutamate, D. Pyridoxine to pyridoxal phosphate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Proline to hydroxyprolineRef: Harpers Biochemistry, 30th ed. pg. 47, 562* Ascorbic acid is needed for a variety of biosynthetic pathways, by accelerating hydroxylation and amidation reactions.* In the synthesis of collagen, ascorbic acid is required as a cofactor for following enzymes:# Prolyl hydroxylase# Lysyl hydroxylase* These two enzymes are responsible for the hydroxylation of the proline and lysine amino acids in collagen.* Remember, Hydroxyproline and hydroxylysine are important for stabilizing collagen by cross-linking the propeptides in collagen.* Clinical effects if there is defective collagen fibrillogenesis:# Impaired wound healing.# Impaired bone bormation# Abnormal bleeding due to fragile capillaries.', 'role': 'assistant'}]