Question

The enzyme which converts carbon dioxide in the RBCs into carbonic acid, protons and bicarbonates and its co-factor is

• A. Carbonic anhydrase and magnesium
• B. Carboxylase and sodium
• C. Carboxylase and zinc
• D. Carbonic anhydrase and zinc

Answer 1

The correct option is D

Carbonic anhydrase and zinc

Carbonic anhydrase is an enzyme that assists rapid inter-conversion of carbon dioxide and water into carbonic acid, protons and bicarbonate ions. This enzyme was first identified in 1933, in red blood cells of cows. Since then, it has been found to be abundant in all mammalian tissues, plants, algae and bacteria. This ancient enzyme has three distinct classes (called alpha, beta and gamma carbonic anhydrase). Members of these different classes share very little sequence or structural similarity, yet they all perform the same function and require a zinc ion at the active site.