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': 'Who was the first to determine the sequence of a polypeptide? \nSelect and explain. \nA. Pehr Edman, B. Frederick Sanger, C. John Kendrew, D. Oakley Fulthrop', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Sanger was the first to determine the sequence of a polypeptide. Mature insulin consists of the 21-residue A chain and the 30-residue B chain linked by disulfide bonds. Frederick Sanger reduced the disulfide bonds, separated the A and B chains, and cleaved each chain into smaller peptides using trypsin, chymotrypsin, and pepsin.\nRef: Harper’s illustrated biochemistry. 30th edition page no: 29', 'role': 'assistant'}]