After fifty years of research, scientists have finally unraveled the molecular mechanics of the bacterial flagellar motor. This sophisticated biological machine allows single-celled bacteria to swim toward nutrients or tumble randomly to find new directions. Recent breakthroughs using cryo-electron microscopy have revealed how protein stators act as turnstiles, driven by a constant influx of protons known as the proton motive force. This mechanism converts entropic energy into kinetic rotation, providing a fundamental look at the physical forces that power cellular life.
Despite winning the Nobel Prize in 2016, a clear definition of 'molecular machine' remains elusive. IUPAC is launching a project to establish consistent terminology in the field, seeking input from researchers to avoid semantic debates and potential legal issues.
