Biology Reference
In-Depth Information
Fig. 3. The Petri net
P
rev
with reversible reactions.
Hence,
l
2' must be prevented from occurring for tokens
x
=
C. In the course of
PPP
, one G- and two
H-molecules on G6P are transformed into one H-token on
GAP 1
(via
r
5) and two H-tokens on
F6P 2
(via
r
4 and
r
5).
For the latter H-tokens there are three possibilities to be processed further:
1. both move to FBP via
l
3 and continue on the 'normal' way to Lac,
2. both move to G6P via
l
2' and thus regenerate the initial two H-tokens there,
3. one of them is moved by
l
3 to FBP, and the second one by
l
2' to G6P. This case is a combination
of glycolysis and
gluconeogenesis
, which cannot occur in steady state.
