Final answer:
A cell must have G protein-coupled receptors to respond to epinephrine. The binding of epinephrine activates a G-protein and triggers a cascade of intracellular events, allowing for cell-specific responses through second messengers.
Step-by-step explanation:
In order for a cell to respond to the signaling molecule epinephrine, it must have G protein-coupled receptors. These receptors are activated when epinephrine binds to them, which then activates a G-protein. This leads to the activation of adenylyl cyclase, converting ATP to cAMP. cAMP acts as a second messenger in various signaling pathways inside the cell, mediating responses that are specific to the cell type involved. Therefore, despite the use of the same second messengers, different cells can respond uniquely based on their own set of proteins and cellular context.