[Quantitative relationships in the theory of active transport]

Quantitative relations for the active transport across a membrane are derived according to Mitchell's theory using an approach based on thermodynamic and kinetic principles. The main formula predicts that the flow rate depends on the "oxidative power" of the membrane in case of a big ionic flow. In case of a low current the rate is determined by the redox potential of the respiratory substrate. The relations derived in the paper are in qualitative agreement with Kaback's data on the active transport in bacterial vesicles.