Flagella

Definition

Flagella are long, whip-like structures that protrude from the cell membrane and enable cellular movement. They are primarily composed of proteins and found in both eukaryotic and prokaryotic cells.

5 Must Know Facts For Your Next Test

1. Eukaryotic flagella are made up of microtubules arranged in a '9+2' structure.
2. The movement of eukaryotic flagella is powered by ATP through the action of dynein motor proteins.
3. Flagella differ structurally between eukaryotes and prokaryotes; in eukaryotes, they are covered by the cell membrane.
4. Not all eukaryotic cells have flagella; for example, most plant cells do not possess them.
5. Flagella can also play a role in sensory functions, helping cells to detect changes in their environment.

Review Questions

• What structural arrangement characterizes the microtubules within eukaryotic flagella?
• How is the movement of eukaryotic flagella powered?
• Do all eukaryotic cells have flagella? Provide an example.

Related terms

Cilia:

Short, hair-like structures on the cell surface that also aid in movement and sensory functions.

Microtubules: Cylindrical structures composed of tubulin proteins that provide support and shape to cells and form part of the cytoskeleton.

Dynein: A motor protein that moves along microtubules and powers the beating motion of cilia and flagella.