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Engineering Approaches to Biomolecular Motors: From in vitro to in vivo Poster Abstracts
59
2-POS
Board 2
Maximizing Irreversibility and Minimizing Energy Dissipation for Simple Models of
Mechanochemical Machines
Aidan I. Brown
, David A. Sivak.
Simon Fraser University, Burnaby, BC, Canada.
Driven reactions and processes at microscopic scales must overcome fluctuations to proceed
forwards more than they go in reverse. It is well known that some free energy dissipation is
required to achieve irreversible forward progress, but the detailed relationship between
irreversibility and free energy dissipation is not well understood. We present results for the
irreversibility-dissipation relationship of a model system which captures the basic physics of
energy storage. Such a system can represent many examples – ATP synthase completing
unfavourable rotations to synthesize ATP, linear walking motors changing conformation prior to
a power stroke, and viral packing motors translocating against the pressure of a polymer trying to
escape. Our analysis reveals that reactions which do not carry a system far beyond the energy
storage step can achieve equal irreversibility while reducing dissipation. Our results also suggest
scenarios where a system must pay a higher dissipation cost for a relatively low irreversibility.
We discuss how our investigation points towards general principles of microscopic machine
operation and process design.