<prompt> Rate limiting enzyme in catecholamine synthesis-Dopa decarboxylaseN-methyltransferaseDopamine hydroxylaseTyrosine hydroxylase  <response>: Ans. is d i.e., Tyrosine hydroxylase DopaTyrosine hydroxylase--- Tyrosinase ..--- DopaTyrosineDopa decarboxylase TyrosinaseDopamine Throxine T4Dopaquinoneb-oxidaseTriiodothyronineb-bydroxylase NorepinephrineMelaninN -methyl transferase N-methylationEpinephrineo Tyrosine hydroxylase is the rate limiting enzy me in the synthesis of catecholamines and it catalyzes the con version of ty rosine into dopa.o Immediate precursor of norepinephrine is dopmine. 