Wheels against wheels (opens in new tab)

The biological motor that powers the motion of bacteria is now finally understood. Wheels are rare in biology, but they exist. Recent research has completed a project that started with the discovery of a molecular-scale spinning wheel in the 1970s.The only known example of a freely-spinning wheel against a fixed body is the flagellum. It comes in three types, on for each domain of life: bacterial, archaeal, and eukaryotic. Fifty years after the discovery that bacteria move around by spinning ...