The exact mechanism of the many different identified pumps systems is still under discussion. Viewing at those pump systems as consisting of two asymmetrical interface systems with a channel-like bulk phase in between and drawing hypothetical Evans diagrams and considering a missing equipotential plane to locate the different mixed potentials on either site of the membrane one can attribute two different over-potentials on the inner and outer surface as the driving force for the directed flow of ions. Even the known reverse pumping mechanism is easily understandable considering that the equilibrium potential of the corresponding ions at their different binding sites at/on/in the pump changes according to the laws of thermodynamics.
i am working on corrosion research since 1968
i do work on nerve conduction - in 2000
both have mixed potentials
the variation of corrosion potentials are of the orders of 100 mV
Corrosion currents depend on Ea and E c variation and areas ratio variations
but the membrane potentials vary withmax 90mV
electricity conduction matters - in cells the potential is determined by diffusion / crossing of ions through membranes
we can understand furthur
I think measurement of potentials between biological membranes has been going on for certain time. An example:
http://www.sciencedirect.com/science/article/pii/S0003269709001286
I you want to apply electrochemical methods to this systems you will need to design an electrochemical cell with electrodes at both sides of the membrane.
Does this answer your question?
Thanks Roberto for your comment. I know those measurements and the Post-scheme very well. But, I just want to consider the application of a theoretical treatment with hypothetical current-voltage curves for the ions producing a mixed potential (steady-state) situation.
In fact i want to understand and derive the expressions for cell interface potential and the charge transfer across the interface
to my surprise there is no CTR across the interface
oxidation/ reduction reactions are taking place homogeneously
The current flowing is due the potential due to concentration gradient
the current propagation follows the transmission line analog
we can discuss furthur
Mr karl Cammann
please tell me if there is CTR across the cell/ solution interface
i can derive rate expressions including mass transfer
WE CAN ANALYSE FURTHUR
Dear colleague, thanks for your interest. To study the electrochemistry of membranes (either of ion-selective electrodes or biomembranes) the vast experience obtained with studies of charge transfers (ion movements) at ITIES “interface between two immiscible electrolyte solutions” (named by Koryta: Electrochim. Acta 24 (1979), 293) is a good starting point. A redox process is not considered in those experiments. I attach a publication to explain the experimental set-up.
ion transfer and electron transfer are quite different
i know ions flow
i seek your help to know whether electrons transfer
charge i mean electron either should get reduced or oxidised
I will try to answer your questions by attaching a longer reply and a suggestion for an experimental proof of the mixed potential concept hypothesis.
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