And cytochrome molecules are proteins that contain heme groups that combine and transfer electrons. Cytochrome C and cytochrome C one are not the same types of molecules. Now, cytochrome C one actually contains a single hein group. But in the structure and complex three, we also have another cytochrome molecule known as cytochrome B. And this molecule actually contains two different heme groups that are capable of actually attaching electrons. And finally, we also have a structure known as the risky group.