Pyruvate kinase is the enzyme that catalyzes the final step of glycolysis. It catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to adenosine diphosphate (ADP), yielding one molecule of pyruvate and one molecule of ATP.[1] Pyruvate kinase is present in four distinct, tissue-specific isozymes, each consisting of particular kinetic properties necessary to accommodate the variations in metabolic requirements of diverse tissues.