Ubiquinol (QH2)

3D ModelNoAI

Ubiquinone, or Coenzyme Q10, is a lipid-soluble mobile coenzyme that is composed of a quinone and 10 isoprene groups. Ubiquinone is present in high concentrations in the mitochondria, where it plays an important role in the final step of cellular respiration, oxidative phosphorylation. Ubiquinone has three redox states: fully oxidized (Q), semiquinone (QH·), and fully reduced (QH2). This allows it to act as an electron carrier in the electron transport chain (ETC) of oxidative phosphorylation. The fully reduced form, ubiquinol (QH2), is shown here.

In Complex I and II of the ETC, molecules of Q are reduced to QH2, which then travel through the mitochondrial lipid bilayer to Complex III. In Complex III, molecules of QH2 enter the Q cycle, where they undergo a series of oxidation-reduction reactions.

This model was generated using the web-based 3D model viewer MolView and Jmol, an open-source viewer for molecular structures. Chemical elements in the molecule were colored according to the CPK coloring system.