Electron Transport Chain Complex Proteins (ETC Complex Proteins)

The electron transport chain (ETC) complex proteins are a series of large, multiprotein complexes embedded in the inner mitochondrial membrane. They play a central role in cellular respiration by transferring electrons through redox reactions and pumping protons to generate an electrochemical gradient, which is ultimately used for ATP synthesis via oxidative phosphorylation. The ETC consists of five main complexes: Complex I (NADH:ubiquinone oxidoreductase), Complex II (Succinate dehydrogenase), Complex III (Cytochrome bc1 complex), Complex IV (Cytochrome c oxidase), and Complex V (ATP synthase/F1FO ATP synthase). These complexes transfer high-energy electrons derived mainly from NADH and FADH2 through a series of redox reactions and pump protons into the intermembrane space, creating an electrochemical gradient known as the proton motive force. This gradient drives ATP synthesis as protons flow back into the matrix through ATP synthase. Defects or inhibition at any point in these complexes can lead to impaired energy production with wide-ranging effects on cell viability.

Other names

Respiratory Chain ComplexesMitochondrial Respiratory ComplexesComplex IComplex IIComplex IIIComplex IVComplex VNADH:ubiquinone oxidoreductaseSuccinate dehydrogenaseCytochrome bc1 complexCytochrome c oxidaseATP synthaseF1FO ATP synthase

Inhibition of electron transport, disruption of proton gradient, inhibition of ATP synthesis