View the animation below, then complete the quiz to test your knowledge of the concept.

1	A ligand is...
	A)	a small molecule that binds to the alpha subunit of the G-protein.
	B)	a small molecule that binds to a membrane-bound receptor.
	C)	a large molecule that binds to the alpha subunit of the G-protein.
	D)	a large molecule that binds to a membrane-bound receptor.
	E)	a small molecule that binds to a G-protein.
2	Initially, bound to the alpha subunit of the G-protein is...
	A)	a ligand.
	B)	a GTP molecule.
	C)	a GDP molecule.
	D)	an ADP molecule.
	E)	a GTO molecule.
3	As a result of the ligand binding to its site...
	A)	the G-protein changes conformation and GTP replaces the GDP on the alpha subunit.
	B)	the G-protein changes conformation and the alpha subunit separates from the beta and gamma subunits.
	C)	the G-protein changes conformation and GDP replaces the GTP on the alpha subunit.
	D)	the G-protein changes conformation and the alpha subunit rejoins the beta and gamma subunits.
	E)	the G-protein changes conformation and GTO replaces the GTP on the alpha subunit.
4	The alpha subunit’s separatism from the remainder of the G-protein can be repeated as long as the ligand is bound to the receptor.
	A)	True
	B)	False
5	Inactivation of the alpha subunit occurs when its own phosphorylase activity removes a phosphate from the GTP.
	A)	True
	B)	False