Metabolic Engineering: kinetics 2
The next highly oversimplified computer simulation is
Exercise 2 that shows how concentrations in a cyclic pathway depend
on rate coefficients. When one rate coefficient is small compared to the others,
it favors accumulation of its reactant. An interesting point is that a mutation that
impairs a rate is not necessarily lethal. The cell may carry on with little impairment
while the biochemical of industrial interest accumulates.
The reaction sequences are:
The green circles show the biochemical to inspect and the coefficients being maniplated. As the Java simulation was developed, another scrollbar was added to let you manipulate k1 as well as k4. Each change does not start from the beginning; the initial concentrations are those at the end of the previous trial.
Again this figure is not meaningful by itself, and several runs should be compared. Note that setting both k1 and k2 to low values causes two biochemicals to accumulate at the expense of the others. The concentrations
depend very much on the relative magnitudes of the reaction rate coefficients.
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bungay@rpi.edu while on sabbatical leave in Porto, Oct. 1996
Java added in May, 1998