Kinetics: Enzymes and Electrons
In the last chapter we discussed the general principles of kinetics and drew heavily on simple molecular interactions in a vacuum, in other words, gas behavior. This has allowed us to use kinetic theory to discuss the important abstraction of the potential energy surface. Yet most of the reactions of interest to the biologist and biophysical chemist occur in solution. We have drawn a fairly detailed picture of the molecular interactions that complicate the description and behavior of solutions. In general, the rate of a reaction in solution cannot occur any more rapidly than the rate of diffusion that brings the reactants together. Diffusion is the result of a chemical potential driving force that affects the motion of chemical species. We have also seen that the motion of ions in solution can be affected by externally applied electric fields. Finally we have explored how the electric field at the surfaces/solvent interface leads to the important transitional structure of the interphase. We will now see how the rates of surface (binding) reactions and electrochemical processes, which are extremely common in biological systems, are very sensitive to the electrical and chemical potentials at those surfaces.
KeywordsElectron Transfer Potential Energy Surface Electrochemical Reaction Potential Energy Curve Reorganization Energy
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