Plasma coenzyme Q (ubiquinone) concentrations in patients treated with simvastatin.

It transfers electrons between Coenzyme Q - cytochrome c reductase and cytochrome c oxidase.

The reaction mechanism for complex III (Cytochrome bc1, Coenzyme Q: Cytochrome C Oxidoreductase) is known as the ubiquinone ("Q") cycle.

Sporobolomyces species produce ballisto conidia that are bilaterally symmetrical, they have Coenzyme Q or Coenzyme Q(H) as their major ubiquinone, they lack xylose in whole-cell hydrolysates, and they cannot ferment sugars.

Iron-sulfur clusters are found in a variety of metalloproteins, such as the ferredoxins, as well as NADH dehydrogenase, hydrogenases, Coenzyme Q - cytochrome c reductase, Succinate - coenzyme Q reductase and nitrogenase.