Figure 4. Effects of a load on transition times of a toggle switch without the protection assumption.

(A). The time taken to reach 90% of maximum value for the protein undergoing a low-to-high transition as a function of the load. The system is de-dimensionalized as described in Supplementary Text S1 section 1.1 and 3.2.1. (B). The time taken for the concentration of the protein undergoing a high-to-low transition to reach 10% of its maximum value. Note that the linear relationship for both-sided load transition times, and same-sided decay time, and opposite-sided rise time has a negative slope. The relationship for same-sided rise time and opposite sided decay time has a very small, but positive slope.