Fed state:
- Most important hormone acting is insulin
- Insulin activates the kinase component of PFK2
- Kinase component of PFK2 converts fructose 6 phosphate into fructose 2, 6 bisphosphate
- Fructose 2, 6 bisphosphate is the most important allosteric activator of PFK1
- Glycolysis is activated.
Fasting state:
- Most important hormone acting is glucagon
- Glucagon activates the phosphatase component of PFK2
- Phosphatase component of PFK2 breaks down fructose 2, 6 bisphosphate to produce fructose 6 phosphate
- Fructose 2, 6 bisphosphate is the most important allosteric activator of PFK1
- As concentration of fructose 2, 6 bisphosphate decreases, the facilitatory action on PFK1 is decreased
- Glycolysis is inhibited.
