From there, it is then picked up by the final, except the Cytochrome C. And when Cytochrome C accents that electron, it itself is reduced. And that stimulates the detachment of the Cytochrome C is then is able to move along the fluid of the intermembrane space and attach onto complex four, as we'll see in the next lecture. Now, what about that other electron? Well, the second electron moves onto the heme groups of Cytochrome B before actually being picked up by Ubiquinone. Now, this Ubiquinone is not the same one as this Ubiquinone. So complex four, complex three actually contains an additional Ubiquinone that is attached onto a different site.