Mitochondrial Electron Transport Chain Complex III (Complex III)

Mitochondrial electron transport chain complex III, also known as the cytochrome bc1 complex or coenzyme Q:cytochrome c oxidoreductase, is a critical multi-subunit enzyme complex embedded in the inner mitochondrial membrane. It plays a central role in cellular respiration by facilitating electron transfer from ubiquinol to cytochrome c and contributing to ATP synthesis through oxidative phosphorylation. During electron transfer, protons are pumped across the inner mitochondrial membrane, creating an electrochemical proton gradient. The complex follows the Q cycle mechanism. It can also generate reactive oxygen species under stress conditions. Complex III dysfunction is implicated in various pathologies, and it is a target for drugs against malaria and viral infections.

Other names

Cytochrome bc1 complexCoenzyme Q:cytochrome c oxidoreductase

Inhibition of electron transfer within Complex III