But three of these steps, step one, step three and step ten are very exergonic steps. In fact, these are the three steps. So step one, step three and step ten, that essentially make up the majority of the free energy that is released in the process of glycolysis. So remember, in step one we take glucose, use up an ATP molecule neproduct of Hexokinase. We transform that into glucose six phosphate and this releases 33.5 kilojoules of energy. Step three, which is the committed step that's catalyzed by phosphorinase.