So this hydroxyl group on the fourth carbon of the terminal glucose residue of the growing poly of the growing polysaccharide chain, basically attacks this carbon here. Carbon one displacing this entire group and that creates that alpha one four glycocitic bond. Now, notice that glycogen synthase only creates alpha one four glycocitic bonds, but we know glycogen also contains alpha one six glycocytic bonds, about every ten glucose residues. So how exactly do we create alpha one six glycocitic bonds? Well, this is what we're going to focus on in the next lecture. And the final thing that I'd like to mention about glycogen synthase is glycogen synthase can only attach glucose molecules onto a polymer, a growing polysaccharide chain that consists of more than four glucose molecules.