Describe/ explain the transport of the following gases in blood.

a)Oxygen
-Oxygen is in higher concentration in the alveoli/ lungs than in the blood capillaries; hence it diffuses into blood; and into red blood cells; where it combines with haemoglobin to form unstable oxyhaemoglobin; which is then transported by blood into tissues; where there is low oxygen concentration; oxyhaemoglobin dissociates/ breaks down into oxygen and haemoglobin;
b)Carbon (IV) oxide
-Carbon (IV) oxide is in higher concentration in tissues than in blood; it diffuses out of the tissues into blood; and then into red blood cells where it combines with water to form weak carbonic acid; catalyzed by enzyme carbonic anhydrase; weak carbonic acid then dissociates to form hydrogen carbonate ions and hydrogen ions; hydrogen carbonate ions diffuse out red blood cells into plasma and then transported to the lungs; where it is expelled during exhalation.
-Some carbon (IV) oxide (10%) combines with haemoglobin to form carbaminohaemoglobin; which is transported to the lungs; where it dissociates/ breaks down into haemoglobin and carbon (IV) oxide which is expelled during exhalation.
-About 5% of carbon (IV) oxide dissolves in plasma to form weak carbonic acid; to prevent changes in blood pH;