Catecholamines are synthesized from the amino acid _tyrosine_. The synthesis pathway involves several steps: 1. Tyrosine is converted to L-DOPA by the enzyme _tyrosine hydroxylase_. 2. L-DOPA is then converted to dopamine by _DOPA decarboxylase_. 3. Dopamine is converted to norepinephrine by _dopamine β-hydroxylase_. 4. Finally, norepinephrine is converted to epinephrine by _phenylethanolamine N-methyltransferase_.
