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
Catecholamines are synthesized from 
Select and explain. 
A. Tryptophan, B. Tyrosine, C. Methionine, D. Histidine
B: Tyrosine
Answer: B: Tyrosine 
Explanation: Tyrosine -------------------->DOPA ---------------->dopamine ----------------->norepinephrine ----------------->epinephrine (catecholamines)Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 235