This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tryptophan metabolism detail, Subject name: Biochemistry
[{'content': 'Limiting amino acid in maize: \nSelect and explain. \nA. Niacin, B. Tyrosine, C. Tryptophan, D. Methionine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Maize protein Zein lacks tryptophan. As tryptophan is required for the synthesis of Niacin (60 mg of tryptophan is required to make 1 mg of niacin) Hence, In high corn diet, requirement of dietary niacin increases.', 'role': 'assistant'}]