This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Phenylalanine and Tyrosine metabolism Detail, Subject name: Biochemistry
[{'content': 'All of the following are characteristics of phenylalanine hydroxylase, EXCEPT \nSelect and explain. \nA. Mixed function oxidase, B. Tetrahydrobiopterin is a cofactor, C. NADPH provides the reducing power, D. Vitamin C is a cofactor', 'role': 'user'}, {'content': 'Answer: D \nExplanation: PAH is a mixed-function oxidase because it incorporates one atom of oxygen into phenylalanine and another atom of oxygen into H2 to form H2O. Remember: Not all hydroxylase enzymes require Vitamin C. Not all carboxylase enzymes require Vitamin K.', 'role': 'assistant'}]