Question: what is the difference between normal and sickle hemoglobin at the dna?
Answer: Sickle hemoglobin differs from normal hemoglobin by a single amino acid: valine replaces glutamate at position 6 on the surface of the beta chain. ... In a sickled red blood cell, valine 6 (beta chain) binds to a different hydrophobic patch (on the alpha chain, not shown).