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': 'An amino acid that does not form an a-helix is: \nSelect and explain. \nA. Asparagine, B. Tyrosine, C. Tryptophan, D. Proline', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D. ProlineProline which is also called an imino acid always destabilizes a-helix. Other amino acids which disrupt the helix are acidic and basic.', 'role': 'assistant'}]