Theory 26/Cellular/Cell signalling
Noise Is Count Against Volume
The claim
Signalling noise is set by the ratio of molecule number to cell volume, so two cells with the same concentration can differ in noise by an order of magnitude.
01Mechanism
Concentration is the mean; noise depends on how many molecules produce it, which is count, not concentration.
02Prediction
Noise should scale inversely with molecule number.
03Refutation
Noise tracking concentration would remove the counting term.