Adrenaline

• Adrenaline is produced by the adrenal glands.
• Adrenaline is secreted when:

  • Hypoglycaemic
  • Exercisng
  • Stressed.
• Adrenaline raises the blood glucose level by:

  • Binding to receptors on the surface of target cells.
  • Activating an enzyme that causes the breakdown of glycogen to glucose - glycogenolysis.
• The 2nd Messenger Model:

  This process is used by glucagon and adrenaline.

  1. The hormone is the first messenger and binds to receptors on the target cell membrane to form a hormone-receptor complex.
  2. This activates a membrane enzyme, adenylate cyclase, that converts ATP into cyclic AMP- cAMP acts as a second messenger.
  3. The cAMP activates kinase enzyme- which then catalyses the conversion of glycogen to glucose - glycogenolysis.
• The 2nd messenger system causes an amplified/ cascade effect where a small amount of glucagon or adrenaline causes a large release of glucose.