Prokaryotic Cell Structure: Pili

Learning Objectives for "Prokaryotic Cell Structure: Fimbriae and Pili"

After completing this section you should be able to perform the following objectives.

1. State the chemical composition, structure, and function of the short adhesion pili of bacteria.

2. State the function of a bacterial conjugation (sex) pilus.

3. Define bacterial conjugation.

4. State how the ability to change the shape of the adhesive tip of its pili could be an advantage to a bacterium.

5. Briefly describe twitching motility induced by type IV pili.

Highlighted Bacterium

1. Read the description of Neisseria gonorrhoeae and match the bacterium with the description of the organism and the infection it causes.

Think-Pair-Share Questions

Neisseria gonorrhoeae is a gram-negative diplococcus that has the genetic ability to synthesize a number of different and distinct pili as well as a number of different and distinct cell wall adhesins called Opa proteins.

The gonococcus is able to colonize and infect a numerous sites in the body, including the urethra, the rectum, the throat, the conjunctiva of the eye, and the fallopian tubes. It can also colonize sperm.

1. Considering the locations in the body where it colonizes, why doesn't the body simply flush the bacterium out of the body?

2. Why is N. gonorrhoeae able to colonize so many different sites in the body?

3. We recognize pili adhesive tips and cell wall adhesins as foreign and, during adaptive immunity, make antibodies that bind to these microbial molecules. State how this might help to protect the body.

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