1,3-bisphosphoglycerate

Definition

1,3-bisphosphoglycerate is a key intermediate in the glycolysis pathway, which is the first stage of cellular respiration. It is an important high-energy compound that links the energy-releasing reactions of glycolysis to the energy-storing reactions of the citric acid cycle and electron transport chain.

5 Must Know Facts For Your Next Test

1. 1,3-bisphosphoglycerate is the sixth intermediate in the glycolysis pathway, formed from the oxidation of glyceraldehyde 3-phosphate.
2. The conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, catalyzed by phosphoglycerate kinase, is a key substrate-level phosphorylation step that generates 2 ATP molecules per glucose molecule.
3. 1,3-bisphosphoglycerate is a high-energy compound, with a phosphoanhydride bond that stores a large amount of potential energy.
4. The energy stored in the phosphoanhydride bond of 1,3-bisphosphoglycerate is used to phosphorylate ADP, producing ATP through substrate-level phosphorylation.
5. The formation of 1,3-bisphosphoglycerate is an important link between the energy-releasing reactions of glycolysis and the energy-storing reactions of the citric acid cycle and electron transport chain.

Review Questions

• Describe the role of 1,3-bisphosphoglycerate in the glycolysis pathway.
  • 1,3-bisphosphoglycerate is a key intermediate in the glycolysis pathway, the first stage of cellular respiration. It is formed from the oxidation of glyceraldehyde 3-phosphate and serves as a high-energy compound that links the energy-releasing reactions of glycolysis to the energy-storing reactions of the citric acid cycle and electron transport chain. The conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, catalyzed by the enzyme phosphoglycerate kinase, is a crucial substrate-level phosphorylation step that generates 2 ATP molecules per glucose molecule.
• Explain the significance of the phosphoanhydride bond in 1,3-bisphosphoglycerate and how it is utilized in cellular respiration.
  • The phosphoanhydride bond in 1,3-bisphosphoglycerate is a high-energy bond that stores a large amount of potential energy. This energy is used to phosphorylate ADP, producing ATP through the process of substrate-level phosphorylation. The formation of 1,3-bisphosphoglycerate and its subsequent conversion to 3-phosphoglycerate is a critical link between the energy-releasing reactions of glycolysis and the energy-storing reactions of the citric acid cycle and electron transport chain, which are the later stages of cellular respiration. This efficient coupling of energy-releasing and energy-storing processes is a key feature of cellular respiration and allows the cell to maximize the production of ATP from glucose.
• Analyze the importance of 1,3-bisphosphoglycerate in the overall context of cellular respiration and energy metabolism.
  • 1,3-bisphosphoglycerate is a pivotal intermediate in the cellular respiration process, as it serves as a crucial link between the energy-releasing reactions of glycolysis and the energy-storing reactions of the citric acid cycle and electron transport chain. The high-energy phosphoanhydride bond in 1,3-bisphosphoglycerate is utilized to generate ATP through substrate-level phosphorylation, providing the cell with a rapid and efficient means of producing ATP early in the cellular respiration pathway. This ATP production fuels the subsequent energy-storing reactions, allowing the cell to maximize the energy yield from the oxidation of glucose. The formation and conversion of 1,3-bisphosphoglycerate is therefore a critical control point in cellular energy metabolism, highlighting the importance of this key intermediate in the overall context of cellular respiration.

Related terms

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

Phosphoglycerate Kinase: The enzyme that catalyzes the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, generating ATP in the process.

Substrate-Level Phosphorylation: The direct transfer of a phosphate group from a high-energy compound to ADP, resulting in the production of ATP.