Question

What part of hemoglobin is affected in sickle cell anaemia?

• A. $\alpha$-polypeptide chains
• B. $\beta$-polypeptide chains
• C. Both $\alpha$- and $\beta$- polypeptide chains
• D. None of these

Answer 1

The correct option is B $\beta$-polypeptide chains

Hemoglobin has four chains: two alpha chains and two beta chains with heme and iron part along with oxygen. There are some hydrophobic substances (water-hating) present on the surface of proteins. These hydrophobic residues forms cluster and pocket-like structure on the surface of beta chains. These pockets are responsible for diseases like sickle cell anemia also in the beta chain the position of glutamic acid at sixth place in the chain is replaced by valine leading to the shape of red blood cells to be sickle-like due to loss of oxygen.

So, the correct option is 'Beta-polypeptide chains'.