Physico-chemical aspects of some biological membranes. II - Studies on the conductances of the inner membrane of chicken egg in presence of alkali chlorides and the application of absolute reaction rate theory

Membrane conductance of the inner thin membrane of a chicken egg has been studied with aqueous solution of some common alkali chloride, KCl, NaCl, LiCl and NH4Cl. Conductance values were measured for each concentration at different temperatures after bathing the membranes properly in the respective electrolyte solution. The normal behaviour of these conductances shows that the values increase smoothly with increase in concentrations, tending towards limiting values at higher concentrations. The magnitude follow the order NH4+ > K+ > Na+ > Li+ which is the reverse order of the hydrated sizes of these ions. The temperature range studied is between 298 and 323 K at 5 K intervals. The temperature variation of the conductance values has been utilised to calculate the activation energies according to Arrhenius and to Eyring. Assuming the applicability of the absolute reaction rate theory in the membrane conduction process, other thermodynamic activation parameters viz. DeltaG(#), DeltaH(#) and DeltaS(#) have been calculated. The energy values for any particular electrolyte, however, decrease with increase in concentration of the bathing electrolyte. Very small negative DeltaS(#) values indicate, some kind of immobilisation of the ions occurred during the conduction process. (C) 2002 Elsevier Science B.V. All rights reserved.