Question

Which of the following mechanisms can terminate the intracellular signaling pathway once the concentration of the external signal decreases?

a. degradation of the second messenger
b. desensitization of receptors
c. deactivation of a signal transduction protein, such as PKA
d. all of the above

Answer 1

The degradation of the second messenger, desensitization of receptors, and deactivation of a signal transduction protein can terminate the intracellular signaling pathway when the concentration of the external signal decreases.

Step-by-step explanation:

The mechanism that can terminate the intracellular signaling pathway once the concentration of the external signal decreases is degradation of the second messenger, desensitization of receptors, and deactivation of a signal transduction protein such as PKA.

Degradation of signaling molecules and dephosphorylation of phosphorylated intermediates of the pathway by phosphatases are two ways to terminate signals within the cell.