NEET BIOLOGY

Detailed explanation-1: -20-25% of carbon dioxide is transported in the form of carbamino-haemoglobin by RBCs, 5-7% of carbon dioxide is transported in the dissolved state and 70% is transported as bicarbonate.

Detailed explanation-2: -About 88 percent of carbon dioxide in the blood is in the form of bicarbonate ion. The distribution of these chemical species between the interior of the red blood cell and the surrounding plasma varies greatly, with the red blood cells containing considerably less bicarbonate and more carbamate than the plasma.

Detailed explanation-3: -On the venous side of systemic capillaries CO2 enters red blood cells (RBC) where it combines with water to form carbonic acid (H2CO3). This reaction is catalyzed by the enzyme carbonic anhydrase (CA) which is found in RBC’s. Carbonic acid then dissociates to form bicarbonate ions (HCO3-) and hydrogen ions (H+).

Detailed explanation-4: -The benefit of the bicarbonate buffer system is that carbon dioxide is “soaked up” into the blood with little change to the pH of the system. This is important because it takes only a small change in the overall pH of the body for severe injury or death to result.