This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Classification and metabolism of amino acids, Subject name: Biochemistry
Which is not a biological derivative of tyrosine? 
Select and explain. 
A. Melanin, B. Melatonin, C. Epinephrine, D. Dopamine
B: Melatonin
Answer: B: Melatonin 
Explanation: Uses of tyrosine: =Melatonin is formed from tryptophan not from tyrosine Tip to remember:- Tyrosine (smaller name) - Melanin (smaller name) Tryptophan (bigger name) - Melatonin (bigger name) Extra information:- Phenylalanine is conveed to tyrosine by enzyme Phenylalanine Hydroxylase. Therefore tyrosine is non-essential as it can be synthesized in body from phenylalanine. Other uses of tryptophan are- Synthesis of vitamin B3 and serotonin