Now, once we form that activated glucose molecule, we're now ready to actually attach that activated glucose molecule onto that growing glycogen chain. And this is what takes place in this step here. So we take that UDP glucose shown here, and this is our growing glycogen chain. Now, in the presence of an enzyme known as glycogen synthase, what happens is we essentially take the glucose molecule, this structure here, and we attach it onto this region here. More specifically, if we examine the terminal glucose residue that contains a free hydroxyl group on the fourth carbon, this essentially acts as a nucleophile. It attacks this carbon here of the glucose, and it establishes it creates an alpha one four glycositic bond and it displaces, it kicks off this entire molecule here.