Overview
This lecture explains the axial filament, a special type of flagella found in certain spiral-shaped bacteria, and its role in bacterial movement.
Axial Filament Structure and Function
- The axial filament is a unique flagella type, also called an endoflagella.
- It attaches at one end of the cell and wraps around the organism in a spiral fashion.
- It is used for motility, enabling movement similar to a corkscrew or drill bit.
Organisms with Axial Filament
- Axial filaments are found only in spirochete bacteria (spiral-shaped bacteria).
- Key examples include Treponema pallidum (causes syphilis) and Borrelia burgdorferi (causes Lyme disease).
Mechanism of Movement
- When the axial filament contracts, it causes the cell to spin or rotate.
- This spinning action drills the bacterium forward or backward through its environment.
Key Terms & Definitions
- Axial filament — a flagella-like structure inside spirochetes that wraps around the cell, allowing corkscrew movement.
- Endoflagella — another name for axial filament.
- Spirochete — a type of spiral-shaped bacterium.
- Treponema pallidum — spirochete bacterium causing syphilis.
- Borrelia burgdorferi — spirochete bacterium causing Lyme disease.
Action Items / Next Steps
- Memorize the two key spirochete examples and diseases they cause.
- Review diagrams or images of axial filaments in spirochetes for visual understanding.