Functions of Iron:
Formation of hemoglobin: The primary function of iron is to form hemoglobin.
Development of red cell: Iron is not only necessary for hemoglobin synthesis but also for the formation and maturation of red cell.
Oxygen carriage in blood in the form of hemoglobin. 1gm of hemoglobin carries about 1.34 ml of oxygen.
Supplies O2 to muscle: Myoglobin in muscle is an iron containing chromoprotien like hemoglobin.It combines with O2 and acts as an oxygen store for muscle.
Related to tissue oxidation: a. Oxidative production of ATP within the mitochondria involves many iron containing enzymes both heme and nonheme. b. Cytochrome is an iron-containing compound, present in the cell. It functions in the respiratory chain in the transfer of electrons and the storage of energy through alternate oxidation and reduction of iron (Fe++ to Fe+++).
Detoxification: A number of water insoluble drugs and endogenous molecules are transformed by the cytochrome P-450 system (Cytochromes P450 (CYPs) belong to the superfamily of proteins containing a heme cofactor and, therefore, are heme proteins) in the liver into water soluble compounds that can be secreted in bile and eliminated.
Immune System: An adequate iron is necessary for the normal functioning of immune system. Both iron overload and iron deficiency result in changes in immune response. Iron is required by bacteria; therefore iron overload (especially intravenously) may result in increase risk of infection. On the other hand iron deficiency affects humoral and cellular immunity. Concentration of circulating T lymphocytes are reduced in persons with iron deficiency, and mitogenic response is impaired. Natural Killer (NK) cell activity is also reduced. In one study it is proved that the immune response of apparently healthy elderly persons was improved when they were receiving iron supplements. Two iron binding proteins- transferrin in blood and lactoferrin in breast milk appear to protect against infection by withholding iron from microorganisms that need it for proliferation.
Nervous System: Iron is used by brain cells for normal functioning at all ages. It is involved in the function and synthesis of neurotransmitter and, possibly myelin. Nissl granules present in the cytoplasm of the nerve cells, contains organically combined iron. Here iron serves some essential roles probably in oxidation.
Relation with cell nucleus: The chromatin of the nucleus contains iron. It is possible that this iron takes an essential part (may be oxidative) in the functions of nuclei.