Question

The activated G protein stimulates _______________ to produce large amounts of cyclic AMP.

A) a G protein.
B) adenylyl cyclase.
C) protein hormones.
D) protein kinase A.
E) hormone receptors.

Answer 1

The activated G protein stimulates adenylyl cyclase to produce large amounts of cyclic AMP, which in turn activates protein kinases and amplifies the hormone signal. Thus, the option B is the correct answer.

Step-by-step explanation:

The activated G protein stimulates adenylyl cyclase to produce large amounts of cyclic AMP (cAMP). The hormone signal is amplified through this process, as the binding of a hormone to a receptor activates multiple G proteins, which in turn activate adenylyl cyclase. This enzyme catalyzes the conversion of ATP to cAMP, which then activates protein kinases that can phosphorylate many other molecules, further amplifying the signal. The activation of adenylyl cyclase leads to the production of cAMP in the cytosol and subsequently to the activation of protein kinase A (PKA), followed by regulatory phosphorylation of numerous enzymes.