Physiology 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 π‘ Explanation The rate-limiting step in the biosynthesis of catecholamines is catalyzed by β Correct Answer: A. Tyrosine hydroxylase