The Role of the Liver in the Conversion Between Glycogen & Glucose
- The liver plays a vital role in the conversion between glycogen and glucose
- The conversion between these molecules helps to regulate blood glucose concentration
- Both insulin and glucagon have specific receptors on the membranes of liver cells
- When these hormones bind to their receptors they trigger several processes within the liver
- Glycogenesis
- Glycogenolysis
- Gluconeogenesis
Glycogenesis
- Glycgogenesis is the synthesis of glycogen from glucose molecules
- Insulin triggers this process after it detects an increased blood glucose concentration
- The synthesis of glycogen removes glucose molecules from the bloodstream and decreases the blood glucose concentration to within a normal range
- Glycogen acts as a compact and efficient carbohydrate storage molecule
Glycogenolysis
- Glycogenolysis is the breakdown of glycogen to produce glucose molecules
- Glucagon triggers this process after it detects a decreased blood glucose concentration
- It activates enzymes within the liver that breakdown glycogen molecules into glucose
- The breakdown of glycogen releases more glucose molecules to the bloodstream and increases the blood glucose concentration to within the normal range
Gluconeogenesis
- Gluconeogenesis is the synthesis of glucose molecules from non-carbohydrate molecules
- Glucagon also triggers this by activating enzymes within the liver
- These enzymes convert other molecules, such as fatty acids and amino acids, into glucose molecules
- Glucose molecules are released into the bloodstream which increases the blood glucose concentration to within the normal range
Examiner Tip
You may be asked to define the processes above in an exam. Remember that processes with "gen" in their name usually means something has been created or synthesised. Processes with "lysis" in their name usually means something has been broken down.