key term - Fructose-1,6-bisphosphate

Definition

Fructose-1,6-bisphosphate, also known as F-1,6-BP or fructose bisphosphate, is a key intermediate in the glycolytic pathway of carbohydrate metabolism. It is an important regulatory molecule that links the breakdown of glucose to the production of energy-rich ATP molecules within the cell.

5 Must Know Facts For Your Next Test

1. Fructose-1,6-bisphosphate is formed from fructose-6-phosphate through the action of the enzyme phosphofructokinase, which adds a second phosphate group.
2. The formation of fructose-1,6-bisphosphate is a key regulatory step in glycolysis, as phosphofructokinase is allosterically activated by ADP and inhibited by ATP, providing a feedback mechanism to control energy production.
3. Fructose-1,6-bisphosphate is subsequently cleaved by the enzyme aldolase into two triose phosphate molecules, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate, which can then enter further steps of glycolysis.
4. The production of fructose-1,6-bisphosphate is an important control point in carbohydrate metabolism, as it represents the commitment of glucose to the glycolytic pathway and the eventual generation of ATP.
5. Disruptions in the regulation of fructose-1,6-bisphosphate formation, such as through genetic mutations or metabolic disorders, can lead to imbalances in energy production and utilization within the cell.

Review Questions

• Explain the role of fructose-1,6-bisphosphate in the glycolytic pathway.
  • Fructose-1,6-bisphosphate is a key intermediate in the glycolytic pathway, the metabolic process that converts glucose into pyruvate and generates a small amount of ATP. The formation of fructose-1,6-bisphosphate, catalyzed by the enzyme phosphofructokinase, is a crucial regulatory step in glycolysis. This reaction commits glucose to the glycolytic pathway and allows for the subsequent cleavage of fructose-1,6-bisphosphate into two triose phosphate molecules, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate, which can then enter further steps of energy production.
• Describe how the regulation of fructose-1,6-bisphosphate formation is important for controlling energy production within the cell.
  • The regulation of fructose-1,6-bisphosphate formation is a critical control point in carbohydrate metabolism because it represents the commitment of glucose to the glycolytic pathway and the eventual generation of ATP. The enzyme phosphofructokinase, which catalyzes the formation of fructose-1,6-bisphosphate, is allosterically activated by ADP and inhibited by ATP. This feedback mechanism ensures that fructose-1,6-bisphosphate production is increased when energy levels are low (high ADP) and decreased when energy levels are high (high ATP), effectively controlling the rate of glycolysis and energy production within the cell.
• Analyze the potential consequences of disruptions in the regulation of fructose-1,6-bisphosphate formation, and explain how this could impact cellular metabolism and energy homeostasis.
  • Disruptions in the regulation of fructose-1,6-bisphosphate formation, such as through genetic mutations or metabolic disorders, can lead to imbalances in energy production and utilization within the cell. If the formation of fructose-1,6-bisphosphate is dysregulated, it can result in an uncontrolled or inefficient glycolytic pathway, leading to either an excess or a deficiency of ATP production. This can have far-reaching consequences for cellular function, as ATP is the primary energy currency of the cell and is required for a wide range of essential processes. Disruptions in fructose-1,6-bisphosphate regulation may contribute to the development of various metabolic diseases, highlighting the importance of this key intermediate in maintaining cellular energy homeostasis.

Related terms

Glycolysis:

The metabolic pathway that converts glucose into pyruvate, generating a small amount of ATP in the process.

Phosphofructokinase:

The enzyme that catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate, a key regulatory step in glycolysis.

Aldolase: The enzyme that cleaves fructose-1,6-bisphosphate into two triose phosphate molecules, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate.