Electrical Double Layers in Biology

A number of apparently unrelated phenomena in biological systems (e.g., biopolymer aggregation, cell-cell interactions, ion transport across membranes) arise from the special properties of charged surfaces. A sym posium entitled "Electrical Double Layers in Biology", which took place at the Toronto meeting of the Electrochemical Society, 12-17 May 1985, focused on the common features of these phenomena. The papers presented at that symposium are collected here and they illustrate ways in which an under standing of electrical double layers can elucidate a problem in Biology. An example of this approach can be seen from the paper I presented on ion transport and excitation, where the "unusual" ion flows during nerve excitation are actually expected if one includes the effects of electrical double layers at membrane surfaces. Furthermore, the selectivity of the ion channels in these membranes can be better understood on this basis. Other presentations account for such observations as the changes in spacing between muscle proteins during contraction, the interactions of red cells to form rouleaux, the electrical properties of algal cell membranes, electrokinetic potentials during blood flow in arteries, etc. I trust that these papers will indicate the value of electrochemistry in the study of biological systems, an area of research usually called Bioelectrochemistry, and will encourage biologists to use these ideas when approaching related problems.

Contenu
Donnan Potential and Surface Potential of a Charged Membrane and Effect of Ion Binding on the Potential Profile.- An Empirical Relation for the Surface Potential of Phosphatidic Acid Monolayers: Its Dependence on Calcium and the Role of Double Layer Theory.- A Fundamental Question about Electrical Potential Profile in Interfacial Region of Biological Membrane Systems.- The Effect of Water Polarization and Hydration on the Properties of Charged Lipid Membranes.- Influence of the Surface Charge Distribution and Water Layers on the Permeability Properties of Lipid Bilayers.- Facilitation of Ion Permeability of Bilayer Membranes and their Phase Transition.- Single Channel Conductance Changes of Desethanolamine-Gramicidin through pH Variations.- Membrane Potential of Squid Axons.- Electrical Double Layers in Ion Transport and Excitation.- Electrical Double Layers in Pigment-Containing Biomembranes.- Electronic Properties of Electroactive Bilayer Lipid Membranes.- Electron Transfer at Biological Interfaces.- Alterations in Electrical Double Layer Structure Due to Electromagnetic Coupling to Membrane Bound Enzymes.- Transient Impedance Measurements on Biological Membranes: Application to Red Blood Cells and Melanoma Cells.- Measurement of the Frequency-Dependent Impedance across Natural Cell Membranes.- Electrorotation of Single Cells A New Method for Assessment of Membrane Properties.- Recent Studies on Electrokinetic Potentials in Humans.- Effects of pH before and after Deep-Freexe Storage at ?80° C on the Zeta Potentials of Bones.- Electrochemical and Macromolecular Interactions at Red Blood Cell Surface.- The Myosin Filament, Charge Amplification and Charge Condensation.- Donnan Potentials Generated by the Surface Charge on Muscle Filaments.- Long-RangeElectrostatic Forces in Cylindrical Systems: Muscle and Virus Gels.- Contributors.