AST, or Aspartate Aminotransferase, is an enzyme found in various tissues, including the liver, heart, and muscles. It plays a crucial role in amino acid metabolism by facilitating the transfer of an amino group from aspartate to alpha-ketoglutarate, producing oxaloacetate and glutamate. Doctors often measure AST levels in blood tests to assess liver health. Elevated levels may indicate liver damage or disease, but they can also result from conditions affecting the heart or muscles. Therefore, AST is an important marker in diagnosing and monitoring various medical conditions.