Mitochondrial Oxygen Uptake as the Expression of both the One-Trans-Membrane and the Bi-Trans-Membrane Electron Transport Chains

Additional experimental data are presented showing that in rat liver mitochondria, together with the well known one-trans-membrane respiratory chain activity, a bi-trans-membrane electron channelling system, located at the contact sites, is present. This last electron transport pathway promotes the oxidation of substrates present either outside or inside the mitochondria.