PHYSICOCHEMICAL ASPECTS OF SOME BIOLOGICAL-MEMBRANES - I - MEMBRANE-POTENTIALS OF THE INNER MEMBRANE OF CHICKEN EGG IN PRESENCE OF ALKALI CHLORIDES WITHOUT AND WITH CONTROL OF PORES

The inner thin membrane obtained after removing the outer hard cover o f a chicken egg has been found to record membrane potentials when it s eparates two different concentrations of an alkali chloride. The small negative potentials follow the sequence K+ > Na+ > Li+ and more or le ss correspond with the membrane diffusion potentials. When this membra ne is impregnated with potassium zinc ferrocyanide precipitate, the me mbrane potentials are high positive values showing enhanced preference for K+ ions and also follow the order K(+ )much greater than Na+ > Li +. The values, however, are less than the theoretical Nernstian values . Apparent fixed charges developed in this precipitated membrane are c alculated using some classical equations. The comparison shows that th e results with different equations are quite agreeable. In the TMS met hod the charge densities follow the order K+ > Na+ > Li+, but for the other methods it is K+ > Na+ approximate to Li+. (C) 1998 Elsevier Sci ence B.V.