And that phosphoryl group on that serene residue is initially placed onto carbon one. And what that generates is an intermediate molecule known as glucose one six bisphosphate. In the second step that is not shown here, this blue phosphoryl group is transferred back onto that Serene residue and that regenerates the catalytic enzyme, the phosphoglucomutase. And it also generates the final product, glucose one phosphate. And so this phosphoryl group that's attached onto carbon one of the glucose ultimately comes from this enzyme and the enzyme picks up this phosphoryl group shown in blue. Now, once we form glucose one phosphate, in the next step, the glucose one phosphate needs to be activated because by itself, glucose one phosphate cannot simply be added onto the growing glycogen chain because it's not active enough.