Transportation of carbon dioxide Lecture by Dr.Priyanka Dadupanthi, Biyani Girls Colleges.

Oxidation of food generates carbon dioxide. Transportation of this by three ways. Approximately 7 % of this transport in dissolved form, 23%in carbaminohaemoglobin form and 70% in bicarbonate form. CO2 enters into erythrocyte and binds with water molecule in the presence of carbonic anhydrase enzyme and formed carbonic acid. This acid dissociates into hydrogen and bicarbonate ions. Hydrogen ion binds with hemoglobin and formed a buffer molecule haemoglobinic acid. Bicarbonate ion passed out from RBC to plasma and bind with Na/K molecules. Due to this positivity of RBC increase and to restore this chloride ion enters in RBC. This phenomenon is known as chloride shift.