Control of Blood Glucose Concentration (AQA A Level Biology): Revision Note

Glycogenesis, glycogenolysis & gluconeogenesis in the liver

• The liver plays a vital role in regulating blood glucose concentration

• Both insulin and glucagon have specific receptors on the membranes of liver cells

  • Insulin binding activates enzymes that carry out:

    • glycogenesis: the synthesis of glycogen from glucose; this lowers the concentration of glucose in the liver cells and allows more glucose to be removed from the blood by diffusion

  • Glucagon binding activates enzymes that carry out:

    • glycogenolysis: the breakdown of glycogen to produce glucose; this results in diffusion of glucose into the blood

    • gluconeogenesis: the synthesis of glucose molecules from non-carbohydrate molecules, e.g. fatty acids and amino acids; this results in release of glucose into the blood