Cell Biology MCAT Practice Question
A patient presents with severe hemolytic anemia. Red blood cell analysis reveals normal hemoglobin content and oxygen binding curves, but cells exhibit rapid osmotic lysis in hypotonic solutions and accelerated potassium leakage even at rest. Electron microscopy shows fragmented cytoskeletal networks and disrupted membrane anchoring points. Genetic testing identifies a frameshift mutation in the ANK1 gene. Which of the following best describes the primary molecular defect?
Answer choices
- AImpaired oxygen-dependent conformational change in hemoglobin
- BMutations in the AE1 anion exchange channel
- CDecreased expression of band 3 protein in the RBC membrane
- DLoss of ankyrin function disrupting spectrin-membrane protein interactionsCorrect answer
- EDefective Na+/K+-ATPase pump activity
- FSpectrin mutations as alternative cause of hereditary spherocytosis via same scaffold
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