Q. Show the applications in Bioinorganic chemistry?

Bioinorganic chemistry or the study of the role of metal ions in biological cycles is mainly the study of some typical metal complexes of biological importance. These complexes act as oxygen carriers, electron transfer agents, catalyst and as drugs. Out of all the first row transition elements, perhaps iron plays the most important role. The source of energy in human body comes from the oxidation of carbohydrates, proteins and fats. Transfer of electrons from these nutrients to the oxygen molecule is not direct but through a complex chain of molecules. One main electron transfer molecules in the chain is called cytochrome.  It consists of two parts: an iron complex heme and a protein. The iron ion can be either Fe²⁺ or Fe³⁺ the ligand is called by a general name porphyrin. Porphyrin is a name given to a large number of compounds having the same central ring structure but having different substituent groups.