Final answer:
The G-protein normally lies in the resting cell bound to the inactive G-protein-linked receptor. When a ligand binds to the receptor, it activates the G-protein, leading to a series of events that eventually result in the deactivation of the G-protein.
Step-by-step explanation:
The G-protein normally lies in the resting cell bound to the inactive G-protein-linked receptor.
The G-protein is activated when a ligand binds to the receptor, causing a shape change that leads to the release of GDP and the binding of GTP.
The G-protein then splits into the a and By subunits, which may activate other proteins in the cell. After a while, the GTP on the active a subunit is hydrolyzed to GDP, and the G-protein is deactivated.