What reaction is catalyzed by Aspartate Aminotransferase (AST)?

Aspartate Aminotransferase (AST) plays a crucial role in amino acid metabolism and the urea cycle. The correct reaction catalyzed by AST involves the transfer of an amino group from aspartate to alpha-ketoglutarate, resulting in the formation of oxaloacetate and glutamate. This transamination reaction is vital for the conversion of amino acids into metabolic intermediates that can enter the citric acid cycle or be used for energy production.

In this reaction, aspartate, which is an amino acid, donates its amino group to alpha-ketoglutarate, a key component of the citric acid cycle. The outcome is the creation of glutamate, an important amino acid that serves as a nitrogen donor for the synthesis of other amino acids and compounds. Meanwhile, oxaloacetate, the other product of the reaction, can also participate in various metabolic pathways, including gluconeogenesis and the Krebs cycle.

This reaction highlights the interconnectedness of amino acid metabolism with carbohydrate metabolism, demonstrating how amine groups can be shuffled among different substrates to facilitate metabolic needs in the cell.