A True Life Hack: What Physical 'Life Force' Turns Biology's Wheels?
2 days ago
- #proton motive force
- #flagellar motor
- #bacterial movement
- The bacterial flagellar motor is a molecular machine that enables bacteria to move by rotating a flagellum, functioning as an electric motor with speeds over 100 revolutions per second.
- Recent studies since 2020, using cryo-EM, have revealed the motor's structure, showing that stators with a 5:2 protein geometry rotate via proton flow to turn the larger C ring and flagellum.
- The motor switches direction when phosphorylated CheY proteins bind to the C ring, causing it to reshape and rotate clockwise, leading to tumbling; this allows bacteria to navigate toward food via 'run and tumble' behavior.
- The driving force behind the motor is the proton motive force, where protons flow into cells due to concentration gradients, powering cellular processes; this was proposed by Peter Mitchell, who won a Nobel Prize in 1978.
- Cells maintain a proton gradient by pumping protons out via electron transport chains, creating a continuous influx that fuels molecular machines like the flagellar motor, converting entropic energy into kinetic motion.