carbon dioxide transport

Question 1

how is carbon dioxide transported in the body

Answer 1

• 5% is dissolved in the plasma
• 10% is combined with haemoglobin to form carbamino-haemoglobin
• 85% is transported in the form of hydrogen carbonate ions

Question 2

explain how carbon dioxide is turned into hydrogen carbonate ions

Answer 2

• respiration in cells surrounding the capillary generates carbon dioxide
• carbon dioxide diffuses through the tissue fluid and plasma to reach the red blood cell
• the red blood cells contain an enzyme called carbonic anhydrase which catalyses the reaction that forms carbonic acid
• carbonic acid dissociates into hydrogen ions and hydrogen carbonate ions

Question 3

what happens after the formation of hydrogen carbonate ions

Answer 3

• the hydrogen carbonate ions diffuse out of the red blood cell and is transported in the plasma
• the movement is balanced by the inward flow of chlorine ions into the red blood cell
• the presence of hydrogen ions causes the oxyhaemoglobin to dissociate releasing its oxygen, the haemoglobin binds to the hydrogen ion forming haemoglobinic acid which prevents a decrease in the pH