And that's in contrast to oxidative phosphorylation that takes place on the proteins of the electron transport chain. So let's finish off with step seven and step eight. So we have an oxidation reduction reaction in step six. And step seven produces or step seven is a hydration reaction. So the fumerate is transformed into a malade via a hydration reaction. So a water basically attacks, or more specifically, a hydroxide of the water attacks this carbon from this side.