How is oxygen transported round the body?
As you breath the oxygen in from the air it is transported round the body by the red blood cells. The cells are full of a compound called HAEMOGLOBIN, which has a strong affinity to oxygen. When oxygen comes into contact with a molecule of haemoglobin, it seizes it and forms a molecule of OXYHAEMOGLOBIN. This moves around the body to where it is needed, whereupon the oxygen is released and the molecule reverts to being haemoglobin. Oxygen also dissolves in the blood plasma and is transported in that way.