Dietary proteins are first broken down to individual amino acids by various enzymes and hydrochloric acid present in the gastro-intestinal tract.^[1] These amino acids are further broken down to α-keto acids which can be recycled in the body for generation of energy, and production of glucose or fat or other amino acids. This break-down of amino acids to α-keto acids occurs in the liver by a process known as transamination, which follows a bimolecular ping pong mechanism.  Wikipedia