A phosphatase is capable of dephosphorylating molecules.What would this enzyme do in a signal transduction pathway that used a kinase cascade?
A)Phosphorylate a transcription factor.
B)Serve as a ligand for the receptor.
C)Activate the cascade.
D)Phosphorylate a receptor.
E)Turn off the cascadE.

Question

Quizplus · Accepted Answer

A phosphatase would dephosphorylate the downstream molecules in a kinase cascade, ultimately leading to turning off the cascade. This is because a kinase cascade depends on the phosphorylation of downstream targets to propagate the signal, and dephosphorylation of these targets by a phosphatase would reverse this process and turn off the signal.

A Phosphatase Is Capable of Dephosphorylating Molecules