flagellar propulsion

Flagellar propulsion is a method of locomotion used by cells, employing a flagellum, which is a hairlike structure. This organelle is found in various organisms, including protozoans, gametes of algae and animals, and most motile bacteria.1

Eukaryotic flagella, common in protozoans and animal sperm, have a "nine-plus-two" arrangement of microtubules within an axoneme, covered by a cell membrane. Their whiplike, undulating motion, powered by ATP, generates force along the flagellum's axis, propelling the cell forward. Bacterial flagella, made of flagellin, rotate like a propeller, driven by the ion gradient across the cell membrane. While effective, flagellar speeds are generally low.12