Essential Biochemistry - Protein Metabolism (Section 11 - No. 13)

Which of the following amino acids is a precursor for the synthesis of epinephrine and norepinephrine?

Tyrosine

Tryptophan

Histidine

Phenylalanine

Tyrosine and phenylalanine are precursors for the catecholamines (epinephrine and norepinephrine).