NST10 - Lect13 iron6 - Iron Most common nutritional deficiency worldwide estimated that 2 billion people may be deficient Excess iron also major problem

1 Iron • Most common nutritional deficiency worldwide - estimated that 2 billion people may be deficient • Excess iron also major problem as free iron is toxic and causes oxidative damage Too much Iron : a. free radical mediated damage b. susceptibility to infection c. risk of heart disease, especially in men Too little Iron : reduced oxygen- carrying capacity and energy generation - especially in women, children Free Radical : an unstable atom with an unpaired electron in its outer shell. Many factors can cause free radical formation: e.g. oxidation reactions, immune system, pollution, radiation, toxic substances Functions of Iron 1. Oxygen transport – Hemoglobin – Myoglobin 2. Enzyme Cofactor – More than 200 enzyme reactions – Ferrous (Fe 2+ ) and Ferric (Fe 3+ ) forms 3. I mmune Function – Generates free radicals Major Iron-containing Proteins 1. Hemoglobin : carries oxygen and carbon dioxide in blood 2. Myoglobin : carries oxygen to muscles 3. Cytochromes : energy generation 4. Ferritin : storage for iron, excess becomes hemosiderin 5. Transferrin : transports iron in blood Heme