The residual protonmotive force in mitochondria after an oxygen pulse.
Both from irreversible thermodynamics and from mass-action kinetics it can be derived that upon anaerobiosis in an oxygen-pulse experiment the protonmotive force across a mitochondrial membrane undergoes a sudden drop. Under representative conditions the protonmotive force after the drop (the residual protonmotive force) is shown to be less than 3 kJ . mol-1 as opposed to steady-state values for the protonmotive force of 19 kJ . mol-1. It is concluded that correction for proton leakage in pulse experiments by back extrapolation underestimate proton leakage. Consequently the observed H+/O stoichiometries must underestimate the true H+/O ratios.
D006863:Hydrogen-Ion Concentration; D008928:Mitochondria / Q000378:metabolism*; D008954:Models, Biological; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D011522:Protons; D013816:Thermodynamics
D011522:Protons