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': 'Metabolites of tryptophan can give rise to all of the following except \nSelect and explain. \nA. Diarrhoea, B. Vasoconstriction, C. Flushing, D. Phenylketonuria', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Phenylketouria is due to deficiency of phenylalanine hydroxylase enzyme. This enzyme catalyzes hydroxylation of aromatic side chain of phenylalanine to generate tyrosine.\nThe conversation of phenylalanine to tyrosine is blocked resulting in the excretion of high amounts of PHENYLPYRUVATE\xa0in urine.\nClinical features:- mental retardation , failure to talk or walk , seizures, tremors.', 'role': 'assistant'}]