Now, this is the terminal glucose molecule that contains the free hydroxyl group on carbon number four of the glucose. And so this is the alpha one four glycocitic bond that will be cleaved by the glycogen phosphorlase. Now, the other reactant of this particular reaction is the orthophosphate. The orthophosphate actually acts as a nuclear file that cleaves this alpha one four glycocitic bond to basically form these two product molecules. We have a glucose one phosphate and we have the glycogen that now contains one less glucose because we removed this terminal glucose molecule here. Now we have this glycogen that contains N minus one number of glucose molecules.