For Each of the Following Sentences, Select the Best Word

For each of the following sentences, select the best word or phrase from the list below to fill in the blanks.Not all words or phrases will be used; each word or phrase should be used only once.
$\begin{array}{lll}\text { adenylyl cyclase } & \text { cholera toxin } & \text { GTPase } \\\text { AMP } & \text { diacylglycerol } & \text { phosphodiesterase } \\\text { ATP } & \text { five } & \text { seven } \\\text { ATPase } & \text { four } & \text { three } \\\mathrm{Ca}^{2+} & \text { GDP } & \text { twelve } \\\text { cAMP } & \text { GTP } & \text { two }\end{array}$

G-protein-coupled receptors (GPCRs) all have a similar structure with __________ transmembrane domains.When a GPCR binds an extracellular signal, an intracellular G protein, composed of __________ subunits, becomes activated.__________ of the G-protein subunits are tethered to the plasma membrane by short lipid tails.When unstimulated, the α subunit is bound to __________ which is exchanged for __________ on stimulation.The __________ activity of the α subunit is important for inactivating the G protein.__________ inhibits this activity of the α subunit, thereby keeping the subunit in an active state.