Reply to Bob Phair,
>This means, as Kacser is quick to point out, that for any step close >to equilibrium, pi will be nearly 1 and the corresponding Z will be >zero. Since R=kappa*Z, this is true of R as well.
Herbert Sauro wrote,
>What you say is correct. The only thing to point out is that this >result is limited to straight-chain pathways where the enzymes are >working below saturation so that the behaviour of the elasticities is >dictate by the degree of reaction equilibrium. It's only in this case >you can...
Can we stop saying "below saturation" when we mean "far below
saturation"? I know Henrik started it (with his "straight chain of
unsaturated enzymes"), but even the Pope can have an off day. When
enzymologists say "unsaturated" they mean v less than about 90% of Vmax.
When you guys say "unsaturated" you mean v less than about 1% of Vmax,
since otherwise the approximations don't approximate. This seems an
intolerably large gap to me, and isn't even justified by everyday
language -- people in ordinary life don't say "unsaturated" when they
mean "nowhere near saturated", if indeed they use the word at all (other
than in talking about unsaturated fats, where they have no idea what it
means).
Athel
