ELECTRON TRANSFER AT BIOLOGICAL INTERFACES.

Although biological mechanisms have had to do with electrochemical concepts since the early 1900's, potential differences in biological systems have been explained mainly in terms of the Nernstian equilibrium concept. The basis of this classical view is thought to apply too widely. It no longer seems necessary to regard potential differences at membranes as caused exclusively by concentration gradients. The occurrence of redox reactions at the membrane solution interfaces (5-8) may have to be taken into account. Experiments indicate that electron transfer occurs across the membrane. However, a major difficulty of electrochemical experiments to test an electrodic hypothesis is that of making electrical connections to the electrode, i. e. , the cell membrane. In this work, membranes are formed on a conducting surface and are used as electrodes to study the electron transfer reactions at the membrane solution interfaces.