The multifarious couplings of energy transduction.

I have attempted to show in this article that biological coupling is of great complexity resembling that in an electronics circuit with many different forms of feed-back control. Major features of the biological apparatus are (i) the control of diffusion (ii) the structural organisation (iii) the simultaneous use of electronic and electrolytic devices. It is important in the analysis of the coupling to discover the regions of space which can equilibrate. I have put the argument for localised reactions. Chemiosmosis, which is not so very different from these schemes, demands more general equilibration. The great uncertainties lie in the energy distribution in the system and the mechanics of ATP formation. Other couplings may be understood more easily e.g. electron/electron, proton/proton, proton/electron, proton/cation, proton/anion.