Which of these happens first in an adrenergic synaptic transmission?
A) ATP is converted to cyclic AMP
B) Adenylate cyclase is activated
C) G protein dissociates from the NE receptor
D) G protein binds to adenylate cyclase
E) Cyclic AMP induces several effects in the cell

Question

Quizplus · Accepted Answer

The first step in adrenergic synaptic transmission is the binding of norepinephrine (NE) to its receptor on the target cell membrane. This causes the G protein to dissociate from the NE receptor, which is the first step in activating the cyclic AMP (cAMP) signaling pathway. Only after G protein dissociation can the downstream effects of cAMP be initiated, such as activation of adenylate cyclase (B) and the subsequent conversion of ATP to cAMP (A), which then leads to several cellular responses (E). So, the correct order of events is C → G protein dissociation → B → A → E.

Which of These Happens First in an Adrenergic Synaptic Transmission