Related Experiment Video
Updated: Aug 10, 2026

Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools
Published on: July 20, 2022
[The effect of isomeric alkyl (C19--C25) methoxybenzoquinones on mitochondrial respiration]
Abstract:
The influence of 2-methoxy-6-alkyl(C19-C25)benzoquinones-1,4 and 4-methoxy-6-alkyl(C19-C25)benzoquinones-1,2 on the respiration of isolated rat liver mitochondria has been studied. As a concentration of each of the quinones increased gradually from zero, the rate of the respiration using NAD-dependent substrates firstly increased but then decreased, 1,2-quinones being the more potent inhibitors. Concurrently, the respiratory control of mitochondria was lowered, indicating uncoupling effect of these quinones. With succinate the latter exhibited moderately accelerating effect. Uncoupled by 2,4-dinitrophenol, the respiration was stimulated by the both preparations in the presence of succinate but was suppressed when NAD-dependent substrates were used. The observed inhibitory effects have been assumed to be caused by a competition between the quinones and endogenous co-enzyme Q for the active site of NADH-dehydrogenase complex of the respiratory chain.
Related Concept Videos
Mitochondrial Membranes
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
The Electron Transport Chain
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...

