Atoms, Bonds & Water | Polarity, Hydrogen Bonds & Hydrophobic Effect (USMLE Step 1)
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A 19-year-old man develops severe back and thigh pain after a long flight. He has had similar episodes since childhood. Hemoglobin is 8.3 g/dL (reference 13.5–17.5), and the reticulocyte count is 9% (reference 0.5–2.5%). A peripheral smear shows elongated, curved erythrocytes. Hemoglobin analysis shows predominantly hemoglobin S with no hemoglobin A.