So this takes place here, here and here. Then the electrons are ultimately accepted by that diatomic oxygen to form water molecules. And in the final step of the electron transport chain, the fact that we have an unequal distribution of H plus ions basically means we have an electrochemical potential difference between the two sides of our membrane. And that allows the ATP synthase to actually use that energy that is stored in that proton gradient to generate these ATP molecules. So we conclude the following the oxidation of the fuel molecules in glycolysis and the citric acid cycle is actually coupled to the oxidative phosphorylation of the ADP to ATP by using this oxygen in protein complex four, by the establishment of this hydrogen ion gradient on the electron transport chain. So what we're ultimately doing in aerobic cell respiration is we're transforming one form of energy into a different form of energy, into a form that we can actually use by the cells of our body.