A-Level CAIE Biology A2 14.1.9—Glucagon cell signalling Question Bank

• Cell signalling example - glucagon control of blood glucose:

- Hormone binding to receptor causes conformational change

- G-protein activation stimulates adenylyl cyclase

- Second messenger cAMP formation

- Protein kinase A activation by cAMP initiates enzyme cascade

- Signal amplification through enzyme cascade by phosphorylation

- Cellular response: final enzyme activates glycogen breakdown