This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': 'Hanup disease, limiting amino acid \nSelect and explain. \nA. Tyrosine, B. Tryptophan, C. Rhenylalanine, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: It&;s an autosomal recessive disease. Absorption of aromatic amino acids from intestine as well as reabsorption from renal tubules are defective Patient improve when put on high protein diet with supplementation of niacin Hence the limiting amino acid is tryptophanRef: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 242', 'role': 'assistant'}]