Cytochrome b-c1 is the second
major protein complex in the electron transport chain. Clicking
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Ubiquinone (pink) delivers
two electrons at a time to cytochrome b-c1 (red).
As each electron makes its way through
the complex, a hydrogen ion, or proton, is pumped from the
matrix space of the mitochondria into the intermembrane space,
helping to maintain the proton gradient.
After affecting the pumping of a proton
across the membrane, the electron leaves cytochrome b-c1 and enters the mobile carrier protein, cytochrome c