Electron transport chain

Electron Transport Chain

The Electron Transport Chain (ETC) is a series of protein complexes and electron carrier molecules within the inner membrane of mitochondria that generate ATP for energy.

Overview

The ETC is the final pathway in the energy-yielding metabolism of aerobic organisms. It is a process of oxidative phosphorylation, using energy released by the oxidation of nutrients to produce ATP. The ETC uses the electrons from electron carriers to create a chemical gradient that can be used to power oxidative phosphorylation.

Components

The ETC consists of four protein complexes: Complex I (NADH dehydrogenase), Complex II (Succinate dehydrogenase), Complex III (Cytochrome bc1 complex), and Complex IV (Cytochrome c oxidase). These complexes are embedded in the inner mitochondrial membrane.

Function

The ETC functions by transferring electrons from NADH and FADH2, produced by the Krebs cycle, through protein complexes to oxygen, which is reduced to water. The energy released in this process is used to pump protons across the inner mitochondrial membrane, creating a proton gradient. This gradient is used by ATP synthase to produce ATP.

Clinical Significance

Defects in the ETC can lead to a number of mitochondrial disorders, including Leigh's syndrome, MELAS, and Leber's hereditary optic neuropathy. These diseases are often characterized by muscle weakness, neurological problems, and organ dysfunction.

See Also

• Mitochondria
• Krebs cycle
• Oxidative phosphorylation
• Mitochondrial diseases

References

Electron transport chain Resources
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