What is Bio-inorganic chemistry ?

• Bio-inorganic chemistry is a fast developing branch of chemistry which explores the role of metallic ( and some non-metallic) elements in biological systems.
• We shall, however, confine our discussion to the role of only the metallic elements.
• Metals such as Na, K, Ca, Mg, whose ions are present in biological systems in bulk quantities, are called bulk metals and metals such as Fe, Cu, Co, Zn, Cr, Mn, Mo, W, Ni etc.,
• Whose ions are present in trace amounts are called trace metals.
• Both the categories of metals are essential for sustaining life.
• There is a large number of biochemicals containing metal ions which play a significant role in biological systems.
• The most important amongst these are myoglobin and haemoglobin the compounds containing iron.
• Both myoglobin and haemoglobin are metal porphyrins which contain the 'haeme' group in their structure.
• The haeme group consists of an iron atom which is coordinated to four nitrogen atoms of porphyrin ring.