Percentage of parameter space where a bistable response is possible for Models A, B, and Ca.

aA|B stands for Model A controlled for Model B. A|C stands for Model A controlled for Model C.ki: kinetic constants for the reactions in the systems shown in Figure 1. SKt: total concentration of SK. RRt: total concentration of RR. TCt: total concentration of third component protein. The parameter space for ki,kj, and kk was scanned between absolute values of 10−6 and 10 for each of the parameters. Sampling was uniform in logarithmic space.bPercentage of the parameter space of ki, kj and kk where bistability is found for Models A, B, and C respectively.cPercentage of the parameter space where bistability is found in Model A controlled for B and for C, respectively.NA Non Applicable. Mono functional systems have k8 = 0. The concentration of TC = 0 in Model A. Model A can not be scanned with respect to the concentration of SK in the controlled comparisons, because SK is independently fixed to make the dynamical response of Model A more similar to those of Models B and C.