Now, by the way, inside the Heme group. So in the oxidized version of Cytochrome C one, that Fe atom basically exists in this form. But when it gains a single electron, so we have an electron coming in. When it gains a single electron, it is reduced into the Fe two plus form. So remember, in the Hen group, we have the iron atom that can actually gain that electron. And when gains that electron, it is reduced.