Which of the following is true about sickle cell hemoglobin?
A) it has a single amino acid substitution in the beta chain
B) it causes a disease that is always fatal
C) it is found as a monomer instead of a tetramer in red blood cells
D) it has a leucine at a position where normal hemoglobin has an isoleucine
E) none of the choices

Question

Quizplus · Accepted Answer

Sickle cell hemoglobin (HbS) is characterized by a single amino acid substitution in the beta chain of hemoglobin, where valine replaces glutamic acid at the sixth position. This mutation is responsible for the altered properties of hemoglobin in sickle cell disease. The other statements are incorrect: the disease is not always fatal, sickle cell hemoglobin still forms tetramers, and the substitution involves valine for glutamic acid, not leucine for isoleucine.

Which of the Following Is True About Sickle Cell Hemoglobin