Brilliant Image
The flagellum is an intricate biological machine that enables bacteria to move through liquids. This image created by Mariana Ruiz Villarreal shows the dozen-or-so parts of the flagellum. As sodium or hydrogen flow across the bacterial membrane, their movement drives the spinning of a rotor, which in turn drives the shaft inside the flagellum's whip-like tail. Some bacteria have flagella that rotate as much as 1,000 times per second, or 60,000 rotations per minute.
