On the relationship between Z delta pH and delta psi as components of the protonmotive potential in Mitchell's chemiosmotic system.

A basic system of oxidative phosphorylation in steady-state taking into account secondary ion translocations has been considered. It could be shown that over a relatively wide range of parameters the relation between the osmotic and the electric component of the proton-motive potential turned out to be constant. Under conditions of a small leakage a simple approximated formula for the ratio of both components could be given. The results allow in all kinetic equations of the oxidative phosphorylation to express the protonmotive potential and its electric component simply by its other component, the pH-dependent potential.