Which of the following amino acids is a precursor to the synthesis of nitric oxide in the body?

A Arginine ✓
B Glutamine
C Aspartic acid
D Lysine

Explanation

Arginine is converted to citrulline and nitric oxide by the enzyme nitric oxide synthase, which plays a crucial role in vascular relaxation and neurotransmission.

Mnemonic

Arginine = Artery relaxer

Source

Berg et al., Biochemistry
Protein Metabolism Biochemistry Amino Acid Metabolism Hard MEDICAL Confidence: high