ABSTRACT
The chemiosmotic hypothesis describes the central feature of biological energy transduction as the creation of a transmembrane proton gradient from redox potential energy of photosynthesis and respiration. The gradient is built up by a series of guided electron transfers within and between membranous proteins that selectively move electrons and protons without compromising the insulation of the membrane. Small protein units have several thousands of atoms integrated into convoluted structures. Attempts to build a complete theoretical description of the behaviour of these systems are forced immediately into drastic simplifications. To relate the tunnelling theory to observation, we must be able to derive an electron transfer rate. However, in the simple quantum mechanical view, an electron will penetrate the barrier to the acceptor well but then return through the barrier back to the donor in a resonant process that depends on the distance between and the relative energy of the wells.
