Complex III

Complex III/Q cycle

-This system has bifurcated electron flow (meaning that the electron pair gets seperated. From here on, only one electron is moving through the steps rather than a pair)

- 4H+ are pumped

1. One electron moves up the FeS clusters to a heme group that then reduces cytochrome C

2. The other electron reduces another CoQ at the Qi site by traveling first through CytB

(The e- split off to Cytochrome C and Qi)

This happens again so that CoQ at the Qi site has 2e- and is regenerated.

Note: In the video, cytochrome C1 is what she is referencing as the Fe-S/Heme groups that transport the e- to cytochrome C, while Cytochrome B is what transfers it to Q.