Living organisms and thermodynamics (Pentcho Valev)

RUMYM at BGEARN.ACAD.BG RUMYM at BGEARN.ACAD.BG
Fri Oct 24 10:57:06 EST 1997


Lukasz Salwinski wrote:
neither absurd nor contradictory if you read the references I mentioned.      <
everybody generating transmembrane diffusion  potentials in liposome systems <
do have to take those into account. and what is measured in such  systems is <
in pretty good agreement with the predictions. but if you are resistant to any<
unfavourable data 'discussion' is pointless...                                <

Lukasz, I have difficulties in finding literature - let me not describe this
in detail. However I am not at all resistent to unfavorable data - on the
contrary, I am full of self-suspicion and in my first discussions I only
expected help to overcome my own problems. However people are pitiless -
the conflict of interest is enormous in this case.
   I know perfectly well that measured diffusion potentials are in agreement
with the predictions. However I claim that if 1) the electrodes are very far
from the membrane and 2) the electrodes are microscopic, the potential will
be different (depending on the electrodes of course). I have asked many
people - nobody knows of an experiment of this kind. The mere fact that you
mention the liposome system shows that quite different experiments have been
done. If I am wrong, you can simply describe the experiment instead of
getting angry and abandoning the discussion.
   As to the system

  10 mM KCl                        M                        0 mM KCl

how can you claim that the K+ concentration in the right-hand compartment,
away from the membrane, is constant and finite? Everybody would tell you
that the double layer extends at a distance not more than 1 nm from the
membrane. There is a recent paper by Robert Alberty in J. Phys. Chem. (one
of the few available journals), maybe of 3 or 4 September, and this is
described there (still I do not agree with the rest of the paper).

Best regards,
Pentcho



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