How is carbon dioxide transported in the blood?
There are 3 ways in which carbon dioxide is transported in the blood: 1. DISSOLVED CO2 Carbon dioxide is much more soluble in blood than oxygen About 5 % of carbon dioxide is transported unchanged, simply dissolved in the plasma 2. BOUND TO HAEMOGLOBIN AND PLASMA PROTEINS Carbon dioxide combines reversibly with haemoglobin to form carbaminohaemoglobin. Carbon dioxide does not bind to iron, as oxygen does, but to amino groups on the polypeptide chains of haemoglobin. Carbon dioxide also binds to amino groups on the polypeptide chains of plasma proteins About 10 % of carbon dioxide is transported bound to haemoglobin and plasma proteins 3. BICARBONATE IONS (HCO3- ) The majority of carbon dioxide is transported in this way Carbon dioxide enters red blood cells in the tissue capillaries where it combines with water to form carbonic acid (H2CO3).
