Final Answer:
It represents the sequential and accurate order of events in GPCR activation for glycogen breakdown, starting with ligand binding and proceeding through G-protein activation, effector activation, and second messenger action. Therefore, the correct answer is option C) C, A, B, D.
Step-by-step explanation:
The correct sequence of steps in GPCR (G-protein coupled receptor) activation involved in glycogen breakdown is as follows:
C) Ligand Binding (Agonist Binding):
The process starts with the binding of a signaling molecule (ligand) to the GPCR, inducing a conformational change in the receptor.
A) G-Protein Activation:
This conformational change allows the GPCR to activate a G-protein by promoting the exchange of GDP for GTP on the G-protein alpha subunit.
B) Effector Activation:
The activated G-protein alpha subunit then activates an effector enzyme, such as adenylyl cyclase, leading to the production of second messengers like cAMP.
D) Second Messenger Action:
The second messengers activate downstream signaling pathways, ultimately leading to glycogen breakdown.
Therefore, the correct answer is option C) C, A, B, D.