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': 'None Not seen in alpha helix ? \nSelect and explain. \nA. Alanine, B. Leucine, C. Proline, D. Isoleucine', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Proline Proline is never found in a-helix as it has imino group (-NH) not amino (-N112).Thus it cannot provide hydrogen for hydrogen bonding, the major stabilizing force of a-helix.Glycine also tends to disrupt a-helix; because of its high flexibility and small size it often induces bends in a-helix.", 'role': 'assistant'}]