The cost-performance tradeoffs in biochemical clocks

Biological systems need to function accurately in the presence of strong noise and at the same time respond sensitively to subtle external cues. One example is the circadian clock in a broad range of biological systems. Biochemical clocks are composed of chemical reactions that consume free energy; they need to operate in a precise period to maintain their biological functions while remaining susceptible to day-night shifts. Moreover, molecular clocks have multiple copies in many living systems. The fluctuations between different clocks introduce even more uncertainty for the performance of their functions. Here we present a series of work on how biochemical clocks can utilize free energy to reduce phase fluctuations, enhance response sensitivity and achieve synchronization between molecular clocks. The free energy cost-performance tradeoffs are given in quantitative relations, from where we outline several design principles for optimal biochemical clocks.