Binding of norepinephrine or epinephrine to a(n) receptor will activate an inhibitory G protein which decreases the activity of adenylate cyclase and therefore cAMP synthesis while the binding of these two neurotransmitters to a receptor will do the exact opposite

Explanation:

Epinephrine uses classical G protein coupled receptor (GPCR) signaling pathway by four different types of membrane receptors in different tissues:

1,, and  

Binding of non-epinephrine or epinephrine to an receptor activates an inhibitory G protein called GI, GI activates cyclic nucleotide phosphodiesterase enzyme which converts cyclic AMP to 5' AMP thus destroys secondary messenger(cAMP)

receptor associated trimeric G protein is GS which activate adenylate cyclase enzyme which catalyze production of a potent secondary messenger called cAMP

but there is no

i guess you forgot putting it.

what is this saying?