The primary difference lies in their structure and location within the cell. Eukaryotic and prokaryotic flagella serve the same purpose of cellular movement, but achieve this in fundamentally different ways.
Key Differences in Flagella Structure and Location
| Feature | Prokaryotic Flagella | Eukaryotic Flagella |
|---|---|---|
| Structure | Simpler; composed of flagellin protein. | More complex; composed of microtubules. |
| Location | Located outside of the plasma membrane. | Attached to the cell at the cell membrane through basal bodies. |
| Mechanism | Rotates like a propeller. | Moves in a whip-like fashion. |
| Energy Source | Proton motive force. | ATP hydrolysis. |
| Size | Typically smaller in diameter. | Typically larger in diameter. |
Structural Composition
- Prokaryotic Flagella: These are made of a protein called flagellin. The structure is simpler, akin to a basic propeller.
- Eukaryotic Flagella: These are complex structures made of microtubules, specifically arranged in a "9+2" array (nine pairs of microtubules surrounding a central pair).
Location and Attachment
- Prokaryotic Flagella: Prokaryotic flagella are located outside of the plasma membrane.
- Eukaryotic Flagella: Eukaryotic flagella are attached to the cell at the cell membrane through basal bodies.
Movement Mechanism
- Prokaryotic Flagella: Rotation drives movement. The flagellum spins around its base like a propeller, pushing (or pulling) the cell through the liquid.
- Eukaryotic Flagella: A whip-like motion propels the cell. This movement is generated by the sliding of microtubules within the flagellum.
Energy Source
- Prokaryotic Flagella: Powered by the proton motive force, utilizing the electrochemical gradient across the cell membrane.
- Eukaryotic Flagella: Powered by ATP hydrolysis.
