The living cell uses a variety of molecular receptors and signaling networks to read and process chemical signals that may vary in space and time. We model the dynamics of such molecular level measurements as Markov processes in steady state, with a coupling between the receptor and the signal. We prove exactly that, when the the signal dynamics is not perturbed by the receptors,  lower bounded by a quantity proportional to the mutual information. Our result is completely independent of the receptor architecture and dependent on signal properties alone, and therefore holds as a general principle for molecular information processing . A Maxwell's Demon performing non-perturbing measurements must produce entropy at a rate greater than or equal to our bound, irrespective of how it is designed .
The living cell uses a variety of molecular receptors to read and process chemical signals that vary in space and time. We model the dynamics of such molecular level measurements as Markov processes in steady state, with a coupling between the receptor and the signal. We prove exactly that, when the the signal dynamics is not perturbed by the receptors, the free energy consumed by the measurement process is lower bounded by a quantity proportional to the mutual information. Our result is completely independent of the receptor architecture and dependent on signal properties alone, and therefore holds as a general principle for molecular information processing .
D
and signaling networks
D
may
A
the free energy consumed by the measurement process is
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. A Maxwell's Demon performing non-perturbing measurements must produce entropy at a rate greater than or equal to our bound, irrespective of how it is designed