This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Amino Acid Metabolism, Subject name: Biochemistry
Tyrosine utilized in synthesis of all except - 
Select and explain. 
A. Melanin, B. Melatonin, C. Dopamine, D. Thyroxine
B: Melatonin
Answer: B: Melatonin 
Explanation: Ans. is 'b' i.e., Melatonin o Dopamine b-hydroxylase is a 'copper ' containing monooxygenase that requires ascorbic acid and molecular oxygen.o It catalyzes the formation of norepinephrine.