Blood hemoglobin with a much higher affinity for oxygen (hemoglobin F) to function under these conditions. CO is carried in blood in three different ways. (The exact percentages vary depending whether it is arterial or venous blood). Most of it (about 70%) is converted to bicarbonate ions by the enzyme carbonic anhydrase in the red blood cells by the reaction CO + HO → HCO → H + ; about 7% is dissolved in the plasma; and about 23% is bound to hemoglobin as carbamino compounds. Hemoglobin, the main oxygen-carrying molecule in red blood cells, carries both oxygen and carbon dioxide.
Blood donation in England and each donation usually gives two or three adult doses. One adult dose of platelets would otherwise require four whole blood donations. Blood is made in the bone marrow. It is composed of red blood cells, platelets, plasma and white blood cells, collectively referred to as blood components. Donations given at regular blood donation sessions are referred to as "Whole Blood". Platelets are very small cells. They work with the clotting factors in plasma to form a mesh "plug" to stop or prevent bleeding. Plasma is the fluid part of the blood. It contains protein, salts and clotting factors. White