How Carbon Dioxide Enters the Blood - Essay Example

It is the most common mode of CO2 transport in the body. The majority of the carbon dioxide content of the body is this way. The process occurs in the blood capillaries, where carbon dioxide enters the red blood cell. It combines with water in the presence of carbonic anhydrase to produce carbonic acid. A process of dissociation takes place where carbonic acid forms hydrogen ions and bicarbonate ions. This reaction allows for the continuous uptake of carbon dioxide into the blood down its concentration gradient as more of it is converted to bicarbonate ions. The body's PH does not vary as haemoglobin readily combines with hydrogen ions. In the lungs, bicarbonate ions are taken back to the red blood cells and converted to carbonic acid, that is, to carbon dioxide, through the enzymatic action of carbonic anhydrase. CO2 is from the body through exhalation.