Which reaction is catalyzed by ALT?

Alanine aminotransferase (ALT), also known as serum glutamate-pyruvate transaminase (SGPT), primarily catalyzes the conversion of alanine to pyruvate. This reaction involves the transfer of an amino group from alanine to alpha-ketoglutarate, resulting in the formation of pyruvate and glutamate. This process plays a crucial role in amino acid metabolism and gluconeogenesis, as pyruvate can be further utilized in energy production or converted into glucose.

The specificity of ALT towards alanine is significant in various metabolic pathways, particularly in the liver. Elevated levels of ALT in the serum can indicate liver damage or dysfunction, making it an important enzyme for clinical evaluations of hepatic health.

Thus, the correct response aligns with the enzyme's primary function and the metabolic pathways it participates in, reinforcing its role in amino acid and carbohydrate metabolism.