The part of a bacterial cell that helps it move is the flagellum.
- The flagellum is a whip-like, helical filamentous structure that protrudes from the bacterial cell surface and acts like a propeller to enable movement
- It consists of three main parts: the basal body (anchored in the cell membrane), the hook (a curved segment), and the filament (the long external part)
- The basal body contains a rotary motor powered by the flow of protons (proton-motive force) across the cell membrane, which causes the filament to rotate and propel the bacterium through its environment
- This rotation can be very fast, reaching hundreds to thousands of revolutions per minute, allowing bacteria to swim and perform chemotaxis (movement toward or away from chemical stimuli)
- The flagellum can rotate in different directions to change the bacterial swimming pattern, enabling forward movement, reversals, and turns
In summary, bacterial motility is primarily driven by the rotating flagellum , which acts as a molecular motor-propeller system embedded in the cell membrane and extending outside the cell
