Alanine aminotransferase ALT , also known as alanine transaminase or glutamate-pyruvate transaminase GPT , is an enzyme that catalyzes the reversible transfer of an amino group from alanine to -ketoglutarate, resulting in the formation of pyruvate and glutamate. The reaction can be represented as follows:Alanine + -ketoglutarate Pyruvate + GlutamateThis reaction is a part of amino acid metabolism, specifically in the process of transamination. Transamination is a crucial step in the catabolism of amino acids, as it allows the removal of the amino group from the amino acid, which can then be converted to urea and excreted from the body. The remaining carbon skeleton can be further metabolized to produce energy or used as a precursor for the synthesis of other molecules.The role of ALT in amino acid metabolism is to facilitate the interconversion of amino acids and -keto acids. This process helps maintain the balance of amino acids in the body, as it allows the conversion of excess amino acids into other metabolites that can be utilized or stored.The balance of amino acids can affect the function of ALT. When there is an excess of alanine or a deficiency of glutamate, the reaction catalyzed by ALT will proceed in the direction of pyruvate and glutamate formation. Conversely, when there is a deficiency of alanine or an excess of glutamate, the reaction will proceed in the direction of alanine and -ketoglutarate formation. The balance of amino acids can be influenced by various factors, such as diet, exercise, and overall health.In summary, alanine aminotransferase ALT catalyzes the reversible transfer of an amino group from alanine to -ketoglutarate, forming pyruvate and glutamate. This reaction plays a crucial role in amino acid metabolism, specifically in the process of transamination. The balance of amino acids can affect the function of ALT, as it determines the direction in which the reaction proceeds.