Theory 07/Micro to Milli/Molecular motors
Motors Pay for Load Noise
The claim
The efficiency of a molecular motor is set by the ratio of stepping rate to load fluctuation frequency, so a fluctuating load costs more than a steady one of the same mean.
01Mechanism
Each step does work against the instantaneous load; fluctuations mean some steps are wasted, and the ratio determines how many.
02Prediction
Efficiency should fall with load variability.
03Refutation
Efficiency tracking mean load would remove the fluctuation.