230
Chapter 6
Figure 6.10 Result o f a pulse addition of the internal m etabolite at t = 0. p/s" is a m easure o f the flux out
o f the system integrated in tim e. The slope o f p/s" is Jn (= 0 .3 1 0 1 ) for large t.
2 . 5 - ------------■-----------------------------------------------------------------------------------------------
Figure 6.11 R esults o f the sam e experim ent as Fig. 6.10, but with random ly added experim ental error.
W hen 10 independent experim ents are m ade, each with 2% random ly distributed noise the average
values are:
C ,J = 0 .8 9 3 3 ± 0 .0 8 5
and
f
= 0.3105 ± 0 .0 0 5 2
(28)
T he flux is w ell determ ined but (considering the necessary w ork to perform the real experim ents) the
flux control coefficient is not very accurate. O ne m ay easily im agine that w ith m ore enzym es in the
pathw ay the calculation o f the flux control coefficients w ould be sw am ped by the experim ental errors.
This is indeed w hat E hlde and Z acchi (1996) point out in a critical study o f the accuracy o f the transient
m ethod.
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