Grossmont-Cuyamaca Community College District TED Talk Discussion

Answer the following questions in your own words!

• According to the video, how does the number of cells in humans compare to the number of bacteria cells on a human being? How many genes make up the human genome? How many more bacterial genes are associated with the human body?

2. What special characteristic does the bacterium Vibrio fischeri have? What happens when Vibrio fischeri are at a low density? a high density?

3. Describe the symbiotic relationship between Vibrio fischeri and the Hawaiian bobtail squid.

4. What is quorum sensing?

5. True or False: the extracellular concentration of quorum sensing molecules increases in proportion to cell number.

6. What do you think would happen if a single V fischeri cell, which was secreting quorum sensing molecules, was placed in an extremely confined space? Explain your answer.

7. Define pathogenicity. How does bacterial quorum sensing play a role?

8. How are bacteria capable of intraspecies and interspecies communication?

9. Bonnie Bassler’s lab is creating anti-quorum sensing molecules in an effort to implement a “behavior modification” approach to therapeutics. What advantages does this have over the traditional use of antibiotics?

10. Describe the basic mechanism of action of these anti-quorum sensing molecules.

11. In the experiment Dr. Bassler described, what happened when experimental animals were treated with anti-quorum sensing molecules in conjunction with pathogenic bacteria ?