crashfrog writes:
In the lac operon, a combination of negative repression by lactose and positive repression by glucose results in the complex regulation of beta-galactosidease, such that:
The problem is that the gene is never all the way on or all the way off. The repressor is "leaky" and allows for low but measurable expression of the lac gene which is vitally important to the function of the operon since this low level of B-galactosidase activity produces the lactose metabolites that turn the gene on in the presence of lactose. You also need to model the binding dynamics (i.e. Kd values) of lactose metabolites with the lac repressor and c-AMP binding dynamics at the promoter site. On top of all of that, you need to model global regulators that can also affect lac expression, all with their own binding dynamics in different environments. Boolean values will simply not cut it.
Biology is much more analog than it is digital, which is the one draw back I see with using computer simulations for mimicking biological systems.