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
Phenylalanine metabolism products are all except 
Select and explain. 
A. Epinephrine, B. Dopamine, C. Melanin, D. Melatonin
D: Melatonin
Answer: D: Melatonin 
Explanation: Phenylalanine is conveed into Tyrosine by the action of enzyme Phenylalanine hydroxylase. Tyrosine is conveed into Melanin, Catecholamines, Dopamine, and Thyroxine through various metabolic pathways.Ref: DM Vasudevan - Textbook of Biochemistry, 6th edition, page no: 233