Why are red blood cells altered in shape in sickle-cell anemia?

Question

Quizplus · Accepted Answer

Sickle-cell anemia is caused by a mutation in the gene that codes for beta-globin, a component of hemoglobin. The mutation results in the substitution of one amino acid (valine) for another (glutamic acid) in the polypeptide chain. This change alters the shape of the red blood cells, making them sickle-shaped, which can block blood vessels and impair oxygen delivery to tissues. Iron is still present in the hemoglobin molecule and lack of oxygen or interference with replication does not cause the alteration in shape. Haemoglobin is not missing two of its polypeptide chains, only the beta-globin chain is mutated. Therefore, the best choice is D.

Why Are Red Blood Cells Altered in Shape in Sickle-Cell