Final answer:
Glutamine is the most important amino acid for maximizing acid excretion in the kidneys.
Step-by-step explanation:
The most important amino acid for maximizing acid excretion in the kidneys is glutamine. Glutamine can be deaminated by the kidney, resulting in the formation of ammonia (NH3) which is excreted into the urine. This process helps in the excretion of hydrogen ions (H+) as ammonium ions (NH4+), leading to the excretion of acid. Glutamine metabolism plays a crucial role in buffering and excreting acid in the body.