Function of blood Blood will transport oxygen, glucose, fats, proteins, hormones, enzymes, platelets, carbon dioxide and electrolytes. Blood is thick and gloopy, from all the solids it carries around the body, it is made up of 55 per cent plasma and 45 per cent solids. 99 per cent of the blood cells are red blood cells, the main role of the red blood cells is to transport the oxygen to the cells. There are millions of red blood cells in the body for example, for every 1mm 3 volume of blood there are 5 million red blood cells. When blood cells are transparent and there are hardly any white blood cells around the body compared to red blood cells. The role of the white blood cell is to fight off infection, killing bacteria and dangerous organisms to remove the disease from the body. Platelets are parts of cells that prevent blood loss through clotting. Platelets need a substance called factor 8 to enable them to become active. Plasma is the liquid part of the blood, which is straw-coloured in appearance, it is the solution in which all solids are carried.