Living cells use readout molecules to record the state of receptors that detect ligands in their environment. This process appears to be similar to measurements made by computational devices, as extensively studied in the literature following Maxwell's demon. But at what level do measurements made by cellular systems map onto computational measurements made, for example, by magnetic devices ? Can cells reach the thermodynamic limit of minimal dissipation for a given measurement accuracy, and , if not, what is the cause? We consider a canonical biochemical network that reads out the state of a receptor and show rigorously how it relates to a measurement protocol of the type studied in the computational literature. We find that regardless of the network parameters , the biochemical network can never reach the thermodynamic limit of efficiency, and faces a tradeoff between accuracy and dissipation that is more severe than and qualitatively distinct from the tradeoff required thermodynamically . We conclude by demonstrating how biomolecules can be used to achieve optimal protocols -- not under the control of a steady-state biochemical network, but rather under the control of exogenously manipulated baths of ATP and ADP. This leads to an experimental system that might be used to test theories on the thermodynamicsof computation .
Living cells use readout molecules to record the state of receptor proteins, similar to measurements or copies in typical computational devices. But is this analogy rigorous ? Can cells be optimally efficient, and if not, why? We show that, as in computation, a canonical biochemical readout network generates correlations; extracting no work from these correlations sets a lower bound on dissipation. For general input , the biochemical network cannot reach this bound, even with arbitrarily slow reactions or weak thermodynamic driving. It faces an accuracy-dissipation trade-off that is qualitatively distinct from and worse than implied by the bound, and more complex steady-state copy processes cannot perform better. Nonetheless, the cost remains close to the thermodynamic bound unless accuracy is extremely high. Additionally, we show that biomolecular reactions could be used in thermodynamically optimal devices under exogenous manipulation of chemical fuels, suggesting an experimental system for testing computational thermodynamics .
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receptors that detect ligands in their environment. This process appears to be
receptor proteins,
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made by computational devices, as extensively studied in the literature following Maxwell's demon. But at what level do measurements made by cellular systems map onto computational measurements made, for example, by magnetic devices
or copies in typical computational devices. But is this analogy rigorous
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reach the thermodynamic limit of minimal dissipation for a given measurement accuracy, and ,
be optimally efficient, and
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what is the cause? We consider
why? We show that, as in computation,
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network that reads out the state of a receptor and show rigorously how it relates to a measurement protocol of the type studied in the computational literature. We find that regardless of the network parameters
readout network generates correlations; extracting no work from these correlations sets a lower bound on dissipation. For general input
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can never reach the thermodynamic limit of efficiency, and faces a tradeoff between accuracy and dissipation that is more severe than and
cannot reach this bound, even with arbitrarily slow reactions or weak thermodynamic driving. It faces an accuracy-dissipation trade-off that is
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the tradeoff required thermodynamically
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. We conclude by demonstrating how biomolecules can be used to achieve optimal protocols -- not under the control of a
and worse than implied by the bound, and more complex
R
biochemical network, but rather under the control of exogenously manipulated baths of ATP and ADP. This leads to
copy processes cannot perform better. Nonetheless, the cost remains close to the thermodynamic bound unless accuracy is extremely high. Additionally, we show that biomolecular reactions could be used in thermodynamically optimal devices under exogenous manipulation of chemical fuels, suggesting
R
that might be used to test theories on the thermodynamicsof computation
for testing computational thermodynamics