During a tumble, the flagella of a bacterium rotate in a clockwise direction and splay out, creating a looping motion. This halts forward progress and allows the cell to reorient itself toward the direction of an attractant.

University of Wisconsin - Madison

Google

The directional movement of a bacterium is determined by the configuration of its flagella. Bacteria navigate their environment by alternating between two primary states: running (moving forward via counterclockwise flagellar rotation) and tumbling (reorienting via clockwise flagellar rotation).

Directional Movement of Bacteria

https://openstax.org/details/books/microbiology/

Microbiology covers the scope and sequence requirements for a single-semester microbiology course for non-majors. The book presents the core concepts of microbiology with a focus on applications for careers in allied health. The pedagogical features of the text make the material interesting and accessible while maintaining the career-application focus and scientific rigor inherent in the subject matter. Microbiology’s art program enhances students’ understanding of concepts through clear and effective illustrations, diagrams, and photographs.

Microbiology is produced through a collaborative publishing agreement between OpenStax and the American Society for Microbiology Press. The book aligns with the curriculum guidelines of the American Society for Microbiology.

OpenStax Microbiology Textbook

During a run, the flagella of a bacterium rotate in a counterclockwise direction, allowing the cell to move forward. In peritrichous bacteria, this counterclockwise rotation causes the flagella to bundle together in a streamlined manner, resulting in efficient, linear movement.

Learn Before

Related