Abstract
The living cell is the ultimate reactive system, reacting to physical and chemical stimuli through cellular processes such as growth, movement, signaling, and division. The standard mathematical model for well-stirred mixtures of interacting molecules is unable to capture this fundamentally reactive nature of a cell. On the other hand, a reactive model that passes a Turing-like test among biologists will rest on answers to many open questions: what is the appropriate notion of state (temporal memory) and how does it change? What roles do space, time, and probability play? What are relevant events and how do they link cellular processes? We explore these and other challenges on the way towards building a virtual molecular biology lab.