Both AST and ALT transfer an amino group to which compound?

The correct answer indicates that both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) transfer an amino group to alpha-ketoglutarate. This process is crucial in amino acid metabolism and the urea cycle, highlighting the role of these transaminases in the interconversion of amino acids and their keto acid counterparts.

In the specific reactions catalyzed by these enzymes, AST transaminates aspartate to produce oxaloacetate, while ALT transaminates alanine to produce pyruvate. Both reactions involve the transfer of an amino group from the amino acid to alpha-ketoglutarate. This transformation is fundamental because it results in the formation of glutamate, which acts as a key amino group donor in various metabolic pathways, including the synthesis of other amino acids and the detoxification of ammonia through the urea cycle.

By facilitating these reactions, AST and ALT play essential roles in the body's metabolism and regulation of nitrogen balance.