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Temperature and electrophysiology?

r norman rsn_ at _comcast.net
Tue Dec 28 09:04:59 EST 2004


On Tue, 28 Dec 2004 09:18:51 GMT, "kenneth collins"
<kenneth.p.collins at worldnet.att.net> wrote:

<snip extensive discussion to keep messages manageable>

Ken, we all have to apportion our time as we best see fit.  I do
understand that it is frustrating for you that we (including myself)
do not take the time to carefully go through your arguments noting
where some might have some validity and noting where others go astray.
But that is simply a fact that you are well accustomed to after these
many years.

You are incorrect on two points.  First:  fever does manifest itself
in brain malfunction (and ultimately death) after a seemingly brief
temperature shift.  However, it does require a temperature on the
order of 40 C, more than a few degrees shift.  The original question
related to a temperature change from 34.5 to 36 (which I misread as a
half degree change).  That is a smaller change over a different range.
Protein structure is maintained by relatively weak bonds that are
easily disrupted by thermal energy.  The structure persists only
because there are a large number of bonds contributing.  However, as
the temperature changes, sufficient bond breakage occurs to allow a
cumulative effect on denaturation.  Evolution ensures that this
phenomenon is restricted to temperatures above the normal range
encountered by the cells.  So at 40 and above, there are rather
destructive changes.  Below 37 there tends to be virtually none.

Second, your shampoo demonstration is another manifestation of
relatively weak intermolecular bonds that, again, are rather more
temperature sensitive than most chemical processes.  These processes
do occur in physical chemistry and even in biophysics.  However once
again evolution ensures that temperature changes within the normal
range encountered by a system are not disruptive of function. 

In my original answer, using the incorrect 1/2 degree change as an
example, I did say that temperature changes of several degrees cause
changes measurable by the experimenter. I just expressed doubt that
these changes are at all significant in the functioning of the cell
and the organism.






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