Glycerol-3-phosphate dehydrogenase (GPDH) is an enzyme that catalyzes the reversible redox conversion of dihydroxyacetone phosphate (aka glycerone phosphate, outdated) to sn-glycerol 3-phosphate. Glycerol-3-phosphate dehydrogenase serves as a major link between carbohydrate metabolism and lipid metabolism. It is also a major contributor of electrons to the electron transport chain in the mitochondria.