Ubiquinone

Definition

Ubiquinone, also known as coenzyme Q10, is a lipid-soluble molecule that plays a crucial role in the electron transport chain within mitochondria. It facilitates the transfer of electrons between complex I and complex III, and between complex II and complex III.

5 Must Know Facts For Your Next Test

1. Ubiquinone is essential for ATP production through oxidative phosphorylation.
2. It acts as an electron carrier shuttling electrons from NADH dehydrogenase (complex I) and succinate dehydrogenase (complex II) to cytochrome bc1 complex (complex III).
3. Ubiquinone gets reduced to ubiquinol (QH2) upon accepting electrons.
4. Deficiency in ubiquinone can lead to mitochondrial dysfunctions and associated diseases.
5. It is both endogenously synthesized in the body and can be obtained through dietary sources.

Review Questions

Related terms

NADH dehydrogenase:

An enzyme also known as complex I that transfers electrons from NADH to ubiquinone.

Cytochrome bc1 complex: Also known as complex III, it receives electrons from reduced ubiquinol for further transfer down the electron transport chain.

Oxidative Phosphorylation: A metabolic pathway where cells use enzymes to oxidize nutrients, thereby releasing energy which is used to form ATP.