Adrenaline (epinephrine) regulates blood glucose levels by initiating glycogenolysis in hepatocytes. This process relies on a specific signaling cascade initiated when adrenaline binds to its target receptor.
Which of the following correctly describes a step in this signaling mechanism?
Adrenaline, acting as a second messenger, diffuses through the membrane to activate intracellular protein kinases.
When adrenaline binds to its cell-surface receptor, it activates adenylyl cyclase, which catalyses the conversion of ATP to cyclic AMP (cAMPcAMPcAMP).
The adrenaline-receptor complex translocates into the nucleus, where it acts as a transcription factor to increase the expression of glycogenolysis enzymes.
Cyclic AMP (cAMPcAMPcAMP) acts as an intracellular enzyme that directly catalyses the breakdown of glycogen into glucose-1-phosphate.
8 exam-style questions on OCR A A Level Biology Hormonal communication. Each one has a worked solution and a mark scheme showing where the marks go.