Question

Which of the following statements is true about carbonic anhydrase?

a) It is found in most tissues
b) It is particularly abundant in red blood cells
c) It catalyzes the conversion of dissolved CO2 to bicarbonate in the tissue
d) It catalyzes the conversion of bicarbonate to CO2 in the lung
e) All of the rest are correct

Answer 1

Carbonic anhydrase catalyzes the reaction converting carbon dioxide and water into carbonic acid, which dissociates into bicarbonate and hydrogen ions, playing a crucial role in CO2 transport and acid-base balance in the blood.

Step-by-step explanation:

Carbonic anhydrase (CA) is a critical enzyme in the transport of carbon dioxide (CO2) in the blood. It catalyzes the rapid conversion of CO2 and water into carbonic acid (H2CO3), which then dissociates into bicarbonate (HCO3-) and hydrogen (H+) ions.

This reversible reaction is integral to the bicarbonate buffer system used in maintaining acid-base balance in the blood and is also vital for CO2 transport from tissues to the lungs. These processes rely on the action of carbonic anhydrase within red blood cells to facilitate the continuous uptake and release of CO2, forming a key part of the body's respiratory function. In the red blood cells, the reaction is: CO2(g) + H2O(l) ⇌ H+(aq) + HCO3-(aq), which is catalyzed by CA containing a Zn2+ ion that enhances reaction speed, vital for efficient gas exchange and pH regulation.