ENERGY TRANSDUCTION BETWEEN A CONCENTRATION GRADIENT AND AN ALTERNATING ELECTRIC-FIELD

A four-state transport protein that has electric charges that move concomitantly with conformational changes can transduce energy in either direction between an alternating membrane potential and a concentration gradient. An alternating electric potential of very large amplitude is considered, and the rapid-equilibrium approximation is used for the conformational changes. This permits deriving simple expressions for the transport flux, the power supplied by the alternating potential, and the power applied to the concentration gradient. © 1990 American Institute of Physics.