Modeling torque versus speed, shot noise, and rotational diffusion of the bacterial flagellar motor.

We present a minimal physical model for the flagellar motor that enables bacteria to swim. Our model explains the experimentally measured torque-speed relationship of the proton-driven E. coli motor at various pH and temperature conditions. In particular, the dramatic drop of torque at high rotation speeds (the "knee") is shown to arise from saturation of the proton flux. Moreover, we show that shot noise in the proton current dominates the diffusion of motor rotation at low loads. This suggests a new way to probe the discreteness of the energy source, analogous to measurements of charge quantization in superconducting tunnel junctions.

• Publication year

  2009

• Venue

  Physical Review Letters

• Publication date

  2009-10-05

• Fields of study

  Biology, Medicine, Physics

• Identifiers
  DOI 10.1103/PhysRevLett.103.248102arXiv 0910.0835PMID 20366231PMCID PMC2874687
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

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