The electron ultimately ends up reducing this copper B. Then that oxidized, cytochrome C leaves and a second reduced cytochrome C binds and gives off an electron. So ultimately, we have two of these cytochrome C molecules, in their reduced form, being oxidized, give off two electrons. One of the electron ultimately ends up reducing the copper B, and the other electron ultimately ends up reducing the heme A three. So this should be the heme A three. And so we summarize this step in the following way.