Animated 5.6 Quiz

What advantage is gained by having so many steps in one signal transduction pathway?

Greater amplification of the signal

Some disease-causing microbes attack the body by turning on or off specific signal transduction pathways. In the disease cholera, the bacterium Vibrio cholerae causes massive diarrhea by interfering with such a pathway. A toxin from this bacterium enters intestinal cells and chemically modifies G proteins. Once modified, the G proteins can no longer cleave GTP into GDP. What would you expect to see within the intestinal cells of a person with cholera?

The G proteins remain activated and continually activate adenylyl cyclase.

_______ is known as a second messenger in the signal transduction pathway involved in the "flight or fight" response.

cAMP

A key property of signal transduction pathways is that one signal molecule binding to a receptor protein in the cell membrane

can result in several thousand events at the end of the pathway.