Physics (Internal)

Dissipation, time asymmetry, and flux for model biomolecular systems

This event is part of the Condensed Matter Theory Seminar Series.

Thermal fluctuations play a significant role in biomolecular systems, notably by preventing them from always proceeding in a preferred direction. With energy dissipation necessary to break detailed balance, we can ask how best to dissipate energy such that a system is driven in the preferred direction. First, by considering a model of microscopic energy storage, the characteristics that allow time-reversal symmetry to be efficiently broken at fixed energy dissipation are examined. I find that an intermediate energy barrier produces unusually high asymmetry. Second, using a biased chemical reaction cycle, I determine how to optimize the distribution of free energy dissipation to various stages of a cycle, to maximize the rate of forward progress. My results show that the flux-maximizing distribution of dissipation depends on the inherent timescales of different transition pathways, as well as the total free energy dissipation available.