Final answer:
The activation of ß-adrenergic receptors in the presence of adrenaline leads to an increase in cyclic-AMP (CAMP) concentration in mammalian hepatocytes. This activation triggers a phosphorylation cascade that promotes glycogen degradation and inhibits glycogen synthesis.
Step-by-step explanation:
The physiological situation that would cause cyclic-AMP (CAMP) concentration of mammalian hepatocytes (liver cells) to increase is the activation of ß-adrenergic receptors in the presence of adrenaline (also known as epinephrine).
When adrenaline binds to ß-adrenergic receptors in liver cells, it activates adenylyl cyclase, an enzyme that converts ATP to CAMP. This leads to an increase in CAMP concentration inside the cell.
Cyclic AMP then activates protein kinase A (PKA), which phosphorylates two enzymes. The first enzyme, glycogen phosphorylase kinase (GPK), promotes the degradation of glycogen into glucose. The second enzyme, glycogen synthase (GS), is inhibited by phosphorylation, preventing the conversion of glucose to glycogen.