[Non]-deterministic dynamics in cells: From multistability to stochastic switching

I will discuss the interplay between ¿traditional¿ deterministic dynamics and stochastic effects in live cells. The main example the lac operon, a set of self-promoting genes, which, together with the enzymes they express, act as a hysteretic switch. Stochastic simulations of the same system predict spontaneous, random switching by individual cells. This behavior can be well described by a simple abstraction. In a broader context, we review a few examples where stochasticity leads to useful and quantifiable behavior that amounts to a hedging strategy on the level of a population of cells. Finally, we describe stochastic simulations of systems with spatial structure, a field with applications from cancer to swarm robotics.