Theory of the passage of alternating current across artificial membranes in the carrier scheme

In the present paper the general form of the admittance of a membrane is found. It is shown that with change in frequency the capacitance and conductivity may pass through an intermediate "plateau". The dependence of conductivity and capacitance of the membrane on the pH of the solution is investigated at low and high frequencies. It is shown that at high frequency the conductivity as a function of pH may both rise and fall depending on the ratio of the parameters. It is also shown that in presence of an equilibrium surface charge associated with ionization of the membrane phospholipids the conductivity may have a maximum as a function of pH both at low and high frequencies.