These are long, filamentous, cytoplasmic appendages that protrude through the cell wall and contain the contractile protein flagellin. They range in length from 12 to 30 m. These are locomotor organs.
These are thin, short filaments (0.1-1.5 m x 4 to 8 nm) that protrude from the cytoplasmic membrane and are also known as pili. They are protein-based (pilin).
It is a strong, rigid structure of peptidoglycan that surrounds the bacterium like a shell and is located outside of the cytoplasmic membrane. It contains accessory specialised components. It has a thickness of 10–25 nm. It gives the cell form.