On Sat, 08 Feb 1997 19:11:21 GMT, pedro at enzyme.demon.co.uk (Pedro
Mendes) wrote:
>On a different note, the only thing that bothers me about steady state
>analyses is that steady states are mostly inexistent in the wild. I know that
>the steady state is used as it is easier to deal with. Maybe it is time we
>depart from this to the more complicated (but more interesting) analysis of
>non-steady states. The late 1980's work you did with Acerenza and Kacser was a
>good starting point, more recently Hans Westerhoff's group has developed MCA
>for oscillating states but we still have a lot to do in this area. Maybe the
>use of simulation will be a great help to let us explore behaviours and find
>regularities (and ultimatly some laws)
In principle, I agree, Pedro. But, the argument that steady states
mostly do not exist must be qualified in terms of the time-frame of
observation in relation to the time-hierarchy of cellular processes.
In almost all experimental situations there will be parts of
metabolism (in the most general meaning of the term) that are in quasi
steady-states that drift as their parameters drift. This allows a type
of modular analysis that MCA as it stands can cope with quite
adequately. In my opinion, this "nested" sort of view of cellular
processes is of great help in simplifying both modelling and analysis.
Jannie
