Question

Which of the following intermediary product of glycolysis plays an important role in high altitude adaptation?

• A. 1,3 – Bisphosphoglycerate
• B. 2,3 – Bisphosphoglycerate
• C. Fructose 1,6 – Bisphosphate
• D. Phosphoenol pyruvate

Hint:

An increase in 2,3-BPG shifts the oxygen-hemoglobin dissociation curve to the right, which decreases hemoglobin's affinity for oxygen and facilitates its release to hypoxic tissues.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Adaptation to high altitudes involves physiological changes to ensure adequate oxygen delivery to tissues despite lower atmospheric oxygen pressure.
One of the primary rapid adaptive mechanisms in erythrocytes involves modifying the oxygen-affinity curve of hemoglobin.

Step 2: Detailed Explanation:
During glycolysis in red blood cells, a shunt pathway known as the Luebering-Rapoport pathway can divert the intermediate 1,3-bisphosphoglycerate (1,3-BPG).
The enzyme bisphosphoglycerate mutase converts 1,3-BPG into 2,3-bisphosphoglycerate (2,3-BPG).
2,3-BPG is an allosteric effector that binds to the central cavity of the deoxyhemoglobin tetramer (T-state).
This binding stabilizes the low-affinity T-state conformation of hemoglobin, shifting the oxygen-hemoglobin dissociation curve to the right.
A rightward shift facilitates the unloading of oxygen to peripheral tissues at lower partial pressures of oxygen.
At high altitudes, tissue hypoxia triggers an increase in red blood cell glycolysis, elevating intracellular 2,3-BPG levels.
This elevation increases oxygen delivery to tissues, compensating for the decreased oxygen saturation in the lungs.

Step 3: Final Answer:
The intermediary product of glycolysis that plays an important role in high altitude adaptation is 2,3-bisphosphoglycerate.