Single membrane in electric field

Abstract

Biological membranes play an important role in the vital activity of a cell. It is these membranes that make it possible to maintain non-equilibrium concentrations of substances in the cytoplasm. The free energy stored in the form of ionic gradients and transmembrane potential differences is used for transmitting information, for electrosynthesis, for performing mechanical work, for reception etc. All of these varied capabilities of biomembranes are essentially based on their excellent barrier properties, combined with their ability to realize selective transport. The latter can be controlled by an electric field. If a membrane loses its barrier function, nothing will prevent the system from a transition to an equilibrium state, but for a cell, equilibrium means death. Therefore the problem of biomembrane stability is of paramount importance. An electric field holds a unique position among the various factors diminishing the membrane stability. The point is that, under normal physiological conditions, in the majority of cells there exists a transmembrane potential difference of several tens of millivolts. This means that the electric field in the membranes amounts to about 105 V/cm, i.e. it is close to the critical field which causes, for example, dielectric breakdown of liquid hydrocarbons. With a further increase in the electric field the biomembranes undergo changes that lead to a considerable (by 5-7 orders of magnitude) increase in their conductance.KeywordsSurface PotentialSurface Charge DensityElectrochemical PotentialPotential ProfileDipole PotentialThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.