This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins bonds and structure, Subject name: Biochemistry
[{'content': 'Most abundant in bone - \nSelect and explain. \nA. Arginine, B. Hydroxyproline, C. Proline, D. Alanine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most abundant protein in bones is collagen. Collagen is formed from glycine proline lysine Proline and lysine are hydroxylated to make OH-proline and OH-lysine. Now, you have to choose between option 2 and 3. As most of the proline in collagen is hydroxyated so best out of these two options is hydroxyproline. Extra information: OH-proline cause extensive hydrogen bonding and hence collagen provide strength to the bones.', 'role': 'assistant'}]