ABSTRACT
Bistability is a ubiquitous dynamical behavior. Instead of a graded response to the stimulus, a bistable molecule toggles between active and inactive states (all-or-none), but the threshold concentration of the stimulus for activation significantly differs from that for deactivation (hysteresis). Biological examples of bistability include the Escherichia coli lac operon, mitogen-activated protein kinase cascades, cell cycle circuits, the insulin signaling pathway, and synthetic gene switches.
