• Functions of different pyruvate metabolic pathways (and their associated cofactors):
  1. Alanine aminotransferase (B6): alanine carries amino groups to the liver from muscle
  2. Pyruvate carboxylase (biotin): oxaloacetate can replenish TCA cycle or be used in gluconeogenesis
  3. Pyruvate dehydrogenase (B1, B2, B3, B5, lipoic acid): transition from glycolysis to the TCA cycle
  4. Lactic acid dehydrogenase (B3): end of anaerobic glycolysis (major pathway in RBCs, WBCs, kidney medulla, lens, testes, and cornea). NAD+ is regenerated from NADH when pyruvate is converted to lactate. NAD+ is used for glycolysis when gyceraldehyde-3-phosphate is converted to 1-3-bisphosphoglycerate.