Patients with chronic hypoxia (low O₂ levels) due to decreased lung function may adapt by increasing their circulating BPG levels. Predict which outcome will be TRUE for such a patient. A) p₅₀ for O₂ will be decreased. B) p₅₀ for O₂ will be increased. C) The R-state of hemoglobin will be favored. D) O₂ binding to hemoglobin will be hyperbolic. E) None of the answers is correct.

Question

Quizplus · Accepted Answer

Chronic hypoxia leads to decreased oxygen levels in the blood, which triggers an adaptation response that increases the level of 2,3-bisphosphoglycerate (BPG) in the circulation. BPG binds to hemoglobin and stabilizes the T state, which favors the release of oxygen from the R state. This allows for more efficient oxygen delivery to the tissues. As a result, the pO2 for a given level of BPG will be lower, since more oxygen will be released due to the binding of BPG. Therefore, the pO2 for a given level of BPG will be decreased (Choice A is incorrect). The increase in BPG levels will actually shift the oxygen-hemoglobin dissociation curve to the right, resulting in increased p50 for a given level of BPG (Choice B is correct). This shift favors the T state of hemoglobin and facilitates oxygen unloading, which is beneficial for oxygen delivery to the tissue (Choice C is incorrect). Hyperbolic binding of oxygen to hemoglobin is characteristic of the R state, which is not favored under chronic hypoxia, since it decreases the delivery of oxygen to the tissue (Choice D is incorrect).

Patients with Chronic Hypoxia (Low O2 Levels) Due to Decreased

Patients with Chronic Hypoxia (Low O₂ Levels) Due to Decreased