# Pili --- **Pili** (singular: pilus) are short, hairlike structures on the surface of some [[prokaryote|prokaryotic]] cells, similar to [[flagella.png|flagella]], but not nearly as long. There are many different types of pili that serve many different functions. ![[pili.png]] ## Fimbriae **Fimbriae** (singular: fimbria) (which is latin for "fringe") are a type of [[pili|pilus]]—sometimes called the "attachment pilus"—that allow bacterial cells to stick to other surfaces. ## Type IV Pili **Type IV [[pili]]** are basically the grappling hooks of bacteria that allow them to move along surfaces. The pili shoots out, attaches to something and then retracts, in a method of movement called "twitching motility". Type IV pili can alos be used to help the bacteria get inside a bigger cell. ## Sex Pili **Sex [[pili]]** are used to allow a bacteria to reach out and grab another bacterial cell to bring them closer together so that they can exchange genetic material. ___