"Guy C. Brown" wrote:
> MCA starts from a number of postulates
> (such as that there is a steady state, [...]
> So that for example if we find that the experimenatly
> measured flux control coefficients do not add up to 1 we can conclude
> that one or more of the postulates is false [...]
One small remark concerning the meaning of the word 'postulate'. I
believe it means the same thing as 'axiom', or some principle accepted
without proof as a foundation for inquiry. That meaning seems different
from a simple 'assumption'.
For example, a postulate of MCA might say "IF the system is at steady
state, and IF some other conditions hold, THEN the flux control
coefficients add up to 1.0". Even if experimental flux control
coefficients do not add up to 1.0, the postulate (hopefully) still holds
but the assumption of steady state (or some other assumption included in
the postulate) might not.
> Virtually all theories I can think of have a similar structure (consisting
> of a mixture of logical and empirical statements). For example
> Enzyme kinetics or Euclidian Geometry.
I never though of chemical kinetics, of which enzyme kinetics is a
somewhat idiosyncratic subset, as axiomatic. Certainly there is no
mathematical proof for Euclid's axioms (by their very nature of being
axioms). There are also the axioms of quantum mechanics, which
associate with certain observable quantities (momentum, energy) certain
differential operators and there is nothing to "understand" about that
association. [N.B.: During my chemistry teaching days, the fact that
there is nothing to "understand" about the quantum Hamiltonian, as
opposed to the classical Hamiltonian in mechanics, was giving the
hardest time to the most talented students.]
In any case, I do believe that all of formal enzyme kinetics could be
reduced ultimately to the mass-action law of Guldberg and Waage (1878,
if I remember correctly: very interesting papers to read even today, by
very young scientists at that time) which is not axiomatic but actually
based on probability theory.
- Petr
_____________________________________________________________________
P e t r K u z m i c, Ph.D. mailto:pkuzmic at biokin.com
BioKin Ltd. * Software and Consulting http://www.biokin.com
