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': 'Flexibility of protein depends on \nSelect and explain. \nA. Glycine, B. Tryptophan, C. Phenylalanine, D. Histidine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Glycine is one among the commonest amino\xa0acids found in protein structure. Being small and\xa0non-polar, glycine\xa0 is\xa0 mostly\xa0 present in\xa0 the interior structure of\xa0 protein.\xa0\nSatyanarayana, Ed 3, Pg 302', 'role': 'assistant'}]