Why is blood red? Because it contains Haemoglobin -- the most important molecule in the human body. In health -- the average person has 4 lbs. of haemoglobin and manufactures seven billion molecules of haemoglobin every second. It carries oxygen from the lungs to the cells and helps the body remove waste carbon dioxide. In sickness -- an estimated one billion people around the world have some disorder related to haemoglobin: sickle-cell anaemia, pernicious...