Ubiquinones represent a vital component in electron transport of the mitochondrial respiratory chain (hydrogen, electron and oxygen carriers). They, therefore, are almost ubiquitously distributed through the species, with the only exclusion of gram positive bacteria and cyanobacteria. Coenzyme Q functions as electron carrier between flavoproteins and cytochrome molecules of the respiratory chain. Well soluble in organic solvents (e. g. acetone, diethyl ether, chloroform) and fats. Virtually insoluble in water.