The diagram below shows the second messenger model of hormone action, which is utilized by certain hormones during the homeostatic regulation of blood glucose concentration.
Which of the following statements correctly describes the molecular mechanisms involved in this pathway, or how they relate to the control of blood glucose concentration?
Both adrenaline and glucagon bind to the same transmembrane receptor on hepatocytes, initiating the G-protein pathway to produce cyclic AMP (cAMPcAMPcAMP).
Active protein kinase, activated by cyclic AMP (cAMPcAMPcAMP), directly phosphorylates and activates glycogen synthase to promote the storage of glucose as glycogen.
The binding of a single hormone molecule to its specific receptor can activate multiple G-proteins, which in turn activate multiple adenylate cyclase enzymes, causing signal amplification.
Insulin binds to its specific transmembrane receptor, activating adenylate cyclase to convert ATP into cyclic AMP (cAMPcAMPcAMP), which then stimulates the insertion of GLUT4 channel proteins into the membrane.
