The Flagellum

Vital Across Domains

Differences in Domains

The Flagellum is one of the few organelles that exists in more than one Domain. Both Eukaryotic and Prokaryotic cell types can have Flagella, and they each use their Flagella differently. In both cases the purpose of the Flagellum is movement, either for unicellular organisms or reproductive haploid cells. In Bacteria, the Flagellum is rotated from its "hook" attached to the plasma membrane and spins like a propeller in a helix shape. In eukaryotic cells, the Flagellum moves like a whip with the expenditure of adenosine triphosphate (ATP).

Structure

Flagella are extracellular organelles that are attached to the cell membrane by basal bodies. The inside of the Flagellum is made up of nine microtubules surrounding two more microtubules. It is capable of movement by the sliding up or down of these microtubules.
flagella & cilia