And so what happens inside our cells is we react to glucose one phosphate with urine triphosphate. So we have the urine and three phosphate groups, UTP. And the enzyme that catalyzes this step is UDP glucose pyrophosphorase. And so what UDP glucose Pyrophosphorase does is it takes this red structure here and attaches it onto this region here, and we form a urine diphosphate glucose molecule, and we also form a pyrophosphate. So this pyrophosphate is basically this section here. Now, the thing about the UDP glucose is it's a much more reactive molecule.