Flagellum (Cilium)AJ SCIELZO

Prokaryotic Flagella

Long, threadlike structures protruding from the outside surface of the cell

Main function is movement

Prokaryotic flagella are protein fibers that extend from the cell

Multiple depending on the species

Prokaryote cont’d

Using the flagella, some bacteria can “swim” up to 70 cell lengths per second.

The bacteria rotates the flagella like screws to move.

The rotary motor uses the energy stored in a gradient that transfers protons across the plasma membrane to power the movement of the flagellum.

This same process is used in the eukaryotic mitochondria and chloroplasts by an enzyme that synthesizes ATP.

Some protists have cilia which are basically smaller scale flagellum

Prokaryotic Cells

Flagellum

Eukaryotic Flagella

A lash-like appendage sticking out of the cell

Primary function is locomotion, but is also a sensory organelle reacting to chemicals and temperature outside the cell.

Example: sperm cell

Prokaryotic vs Eukaryotic Flagellum

The flagella is unique and differs from prokaryotic to eukaryotic.

They differ in protein composition, structure, and methods of propulsion.

Methods of PropulsionProkaryotic They use their flagellum in a

screw-like motion and propel the cell that way.

Eukaryotic These cells move the flagellum

back and forth lashing it around to propel the cell.

Flagella v Cilia