Flagella

Definition

Flagella are long, whip-like structures that protrude from the cell body of certain prokaryotic and eukaryotic cells. They are primarily used for locomotion and can also serve sensory functions.

5 Must Know Facts For Your Next Test

1. Flagella are composed of a protein called flagellin in prokaryotes and tubulin in eukaryotes.
2. Prokaryotic flagella rotate like a propeller, while eukaryotic flagella have a whip-like motion.
3. The arrangement and number of flagella can be used to classify bacteria (e.g., monotrichous, lophotrichous, amphitrichous, peritrichous).
4. Flagella play a crucial role in bacterial pathogenicity by aiding in motility and colonization of host tissues.
5. Eukaryotic microorganisms such as protozoa also use flagella for movement through their environment.

Review Questions

• What is the primary function of flagella in both prokaryotic and eukaryotic cells?
• How do the movements of prokaryotic and eukaryotic flagella differ?
• Why are flagella important for bacterial pathogenicity?

Related terms

Cilia:

Short, hair-like structures on the cell surface that move fluid past the cell or move the cell itself.

Pili:

Hair-like appendages found on the surface of many bacteria that are used for attachment to surfaces or other cells.

Axoneme: The central strand of a eukaryotic cilium or flagellum, typically composed of microtubules arranged in a specific pattern.