cyclic AMP Watch
Do both glucagon and insulin activate adenylate cyclase?
To stimulate glycogenolysis (breaking down of glycogen and form glucose):
1.Adrenaline reaches the cell membrane of a liver cell. As adrenaline is hydrophilic, it cannot pass through the cell membrane (which is partially made up of hydrophobic fatty acids). It needs a second messenger to "send" the messae into the cell.
2. Adrenaline binds to the cell membrane which actiaves adenylyl cyclase.
3. Adenylyl cyclase catalyses the conversion of ATP to cyclic AMP.
4. Cylic AMP activates the enzymes that causes glycogenolysis.
Answering your question:
1. Cyclic AMP acts as a second messenger in glycogenolysis.
2. Adrenaline is the one that activates adenylyl cyclase.