![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
The ____ cycle accommodates the switch between the two-electron carrier ubiquinol (the reduced form of ubiquinone) and the one-electron carriers—hemes b L and b H of cytochrome b , and cytochromes c 1 and c —and results in the uptake of two protons on the N side and the release of four protons on the P side, per pair of electrons passing through Complex III to cytochrome c .