Final answer:
When epinephrine binds to a G-protein-linked receptor, it initiates a signaling cascade that results in a significant increase in cyclic AMP (CAMP) within the cell, which mediates various cellular responses such as glycogen breakdown.
Step-by-step explanation:
When epinephrine attaches to a G-protein-linked receptor, the process of signal transduction results in the formation of a large amount of intracellular cyclic AMP (CAMP).
Epinephrine, also known as adrenaline, is a hormone that is crucial in the body's fight-or-flight response. Through binding to beta-adrenergic receptors on the plasma membranes of cells, epinephrine activates a G-protein. This G-protein then activates adenylyl cyclase, which catalyzes the conversion of ATP to cyclic AMP (CAMP), a second messenger in cellular signaling pathways. The increase in CAMP levels inside the cell ultimately leads to a plethora of cellular responses, including glycogen breakdown in muscle and liver cells to provide an immediate energy source. The process is tightly regulated and ends when CAMP is degraded by phosphodiesterase, thus terminating the signal.
Essentially, the sequence starting from epinephrine binding and ending in a significant cellular response is vital in preparing the body for rapid action, such as during stress or emergency situations.