If a ligand binds to a G protein-coupled receptor but the normal exchange of GDP for GTP on the associated G protein does not take place, what will happen in the cell?
A) Cell responses that depend on an activated effector protein will not occur.
B) GDP binding will cause a conformational change in the G protein-coupled receptor.
C) The GDP-bound subunit will travel through the lipid bilayer.
D) The ligand will not be released from the G protein-coupled receptor.
E) Inactive G protein will be activated.

Question

Quizplus · Accepted Answer

The normal exchange of GDP for GTP is necessary for the activation of the G protein and subsequent activation of downstream effector proteins. If this exchange does not occur, the effector proteins will not be activated and the cell response will not occur.

If a Ligand Binds to a G Protein-Coupled Receptor but the Normal