The rate-limiting step in the biosynthesis of catecholamines is catalyzed by: (A) Tyrosine hydroxylase, (B) Dopa decarboxylase, (C) Dopa mine f3 hydroxylase, (D) Catechol-O-methyltransferase
Answer is A. The rate limiting step in the synthesis of catecholamines is catalysed by tyrosine hydroxylase Ref : guyton and hall textbook of medical physiology 12 edition page number:605,606,607