This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Amino-acid expressed maximally in collagen? \nSelect and explain. \nA. Tyrosine & phenylalanine, B. Alanine & aspaic acid, C. Glycine & cysteine, D. Proline & hydroxyproline', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is `d' i.e., Proline & hydroxyprolineGlycine (33%), proline (10%), hydroxyproline, lysine and hydroxylysine are the predominant amino acids in collagen. Collagen.", 'role': 'assistant'}]