Rate limiting step in catecholamine synthesis:-
Catecholamines are epinephrine, norepinephrine and dopamine. L-DOPA is the precursor of all catecholamines The diagram given below shows the synthesis of L-DOPA and the rate limiting enzyme in the synthesis is tyrosine hydroxylase.
Phenylethanolamine N-methyltransferase
Dopadecarboxylase
Tyrosine hydroxylase
Tryptophan decarboxylase A
Phenylalanine and Tyrosine metabolism Detail