Final answer:
Epinephrine acts on muscle cells through beta-adrenergic receptors, increasing cyclic AMP levels and triggering the conversion of glycogen to glucose.
Step-by-step explanation:
Epinephrine, also known as adrenaline, primarily uses beta-adrenergic receptors when acting on muscle cells. The binding of epinephrine to these receptors on the plasma membrane of cells leads to the activation of a G-protein, which then activates adenylyl cyclase.
This enzymatic action converts ATP to cyclic AMP (CAMP), which functions as a second messenger mediating a specific cellular response. Particularly in muscle cells, this pathway results in increased levels of CAMP, which activates protein kinase A (PKA).
PKA then phosphorylates enzymes involved in glycogen degradation, providing a quick supply of glucose for the muscle during the 'fight-or-flight' response.
When epinephrine acts on muscle, it uses beta-adrenergic receptors. These receptors are of two main types: beta-1 and beta-2. Epinephrine binds to these receptors, which activate a G-protein and increase intracellular levels of cyclic AMP (CAMP), resulting in muscle cell contraction and other cell-specific responses.