Bacteria are a nanotechnological marvel. Consider the bacterium Escherichia coli as an example. Barely a millionth the size of a typical human (E. coli is a rod-shaped cell about 2 µm long and 1 μm wide), each cell is chock-full of molecular machinery that enables it to carry out life’s myriad functions. One of these, the flagellum, is the miniature propeller that allows E. coli to swim at astonishing speeds, covering up to 20 body lengths every second. A typical cell has four or five flagella, each capable of rotating in either direction – clockwise (CW) or counterclockwise (CCW).
