Normal and Sickle-Cell Hemoglobin Molecules Differ

Question

Normal and sickle-cell hemoglobin molecules differ
A)in the number of amino acids in each molecule.
B)by a single DNA point mutation that leads to the substitution of one amino acid for another.
C)in the number and orientation of the amino acid chains attached to the heme portion of each molecule.
D)in the number of oxygen molecules that can be carried by each molecule.
E)by the type of bone marrow that produces them.

Accepted Answer

Normal and sickle-cell hemoglobin molecules differ by a single DNA point mutation that leads to the substitution of one amino acid (valine instead of glutamic acid) for another in the beta-globin chain of the molecule. This structural change alters the shape of the molecule and affects its oxygen-carrying capacity.