Question

The complex II of mitochondrial electron transport chain is also known as ______.

Options

• Cytochrome bc₁

• Succinate dehydrogenase

• Cytochrome c oxidase

• NADH dehydrogenase

Answer 1

The complex II of mitochondrial electron transport chain is also known as Succinate dehydrogenase.

Explanation:

There are five complexes in the mitochondrial Electron Transport Chain (ETC) (I to V). Each complex plays a distinct part in pumping protons and moving electrons.

• Complex I = NADH dehydrogenase
• Complex II = Succinate dehydrogenase (also involved in the Krebs cycle)
• Complex III = Cytochrome bc₁ complex
• Complex IV = Cytochrome c oxidase
• Complex V = ATP synthase

Complex II is unique because it participates in both the Krebs cycle (converting succinate to fumarate) and the ETC. Although it does not pump protons, it transfers electrons from FADH₂ to coenzyme Q (ubiquinone).