Flagella
Start with the big picture
The lesson examines the filament, hook, and basal body, including differences in basal-body ring structure between Gram-negative and Gram-positive bacteria. It explains how motor rotation is powered mainly by the proton motive force, with a sodium gradient used in some vibrios, and how chemotaxis signaling shifts movement between runs and tumbles. Flagellar arrangements describe the number and location of flagella. The topic also connects flagellin and H antigens with immune recognition and bacterial identification, and considers roles in virulence and immune evasion. Laboratory approaches to observing flagella or assessing motility are introduced, alongside a comparison with eukaryotic flagella.
What you'll learn
- Identify the filament, hook, and basal body and describe their roles.
- Explain how energy gradients power bacterial flagellar rotation.
- Relate chemotaxis signaling and rotation direction to runs and tumbles.
- Distinguish flagellar arrangements and their clinical relevance.
- Recognize laboratory methods used to visualize flagella or assess motility.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
