Now, we generate cytochrome C molecules in their reduced form along complex three. And then the cytochrome C in its reduced form, dissociates from complex three and travels and binds onto complex four. And once it binds onto complex four, it transfers an electron initially to the copper A, copper A center. Then the electron goes on to heme A, and then it moves on to heme A three. And that electron ultimately ends up being transferred onto the copper B, and it reduces the copper B. Now, what happens is let me grab purple.