Carbonic anhydrase plays an important role in

RBCs contain a very high concentration of the enzyme carbonic anhydrase which plays an important role in the transport of CO₂.

At the tissues, carbonic anhydrase enzyme present in the erythrocytes catalyses the formation of H₂CO₃ from CO₂  and H₂O and its dissociation into H⁺ and HCO₃^-. At the alveoli, it catalyses the formation of H₂CO₃ from H⁺ and HCO₃^- its dissociation into CO₂  and H₂O.

${\mathrm{CO}}_2 + {\mathrm{H}}_2\mathrm{O} \stackrel{\mathrm{CA}}{\rightleftharpoons }{\mathrm{H}}_2{\mathrm{CO}}_3 + \stackrel{\mathrm{CA}}{\rightleftharpoons } {{\mathrm{HCO}}_3}^{-} + {\mathrm{H}}^{+}$