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': 'Flexibility of protein depends on: \nSelect and explain. \nA. Glycine, B. Tryptophan, C. Phenylalanine, D. Histidine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. GlycineGlycine having the smallest R group fit into small spaces and induces bends in the alpha helix.Glycine is usually present in beta turns.Kinks in protein structure is due to proline.', 'role': 'assistant'}]