Respiratory System MCAT Practice Question
A researcher studies oxygen transport in a patient with chronic hypoxia. Analysis reveals that hemoglobin's P50 value has decreased from the normal 26 mmHg to 18 mmHg. The patient's 2,3-bisphosphoglycerate (2,3-BPG) levels are significantly reduced due to a genetic mutation affecting glycolysis in red blood cells. Which of the following best explains the physiological consequence of decreased 2,3-BPG levels?
Answer choices
- AIncreased oxygen unloading at peripheral tissues due to rightward shift of the oxygen-hemoglobin dissociation curve
- BDecreased oxygen affinity for hemoglobin, resulting in reduced oxygen delivery to tissues despite normal arterial oxygen content
- CIncreased hemoglobin's oxygen affinity, causing leftward shift of the dissociation curve and reduced oxygen release to peripheral tissuesCorrect answer
- DEnhanced cooperative binding of oxygen molecules due to stabilization of hemoglobin's T state
- ECompensatory increase in cardiac output to maintain oxygen delivery despite normal hemoglobin function
- FDecreased hemoglobin's oxygen affinity leading to rightward shift of the dissociation curve and increased oxygen release at the lungs
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