And once inside the cytoplasm of liver cells. An enzyme known as glycerol kinase traps that glycerol inside that liver cell and it traps it by giving it a negative charge. So it actually takes off a phosphoryl group from an ATP, places it onto the oxygen of glycerol, forms an ATP, as well as the l isomer of glycerol three phosphate. And this traps the glycerol inside that particular liver cell. Now what happens next is that glycerol three phosphate is transformed into dihydroxy acid zone phosphate by the enzyme glycerol phosphate dehydrogenase and it also actually reduces the NAD plus and generates NADH. So this is essentially an oxidation reaction where the glycerol three phosphate is oxidized into the dihydroxy acetone phosphate.