Name some metal complex that are present in our biological system and their role in it.

Explanation

(i) A red blood corpuscles (RBC) is composed of heme group which is ` Fe^(2+) ` Porphyrin complex.It plays an important role in carrying oxygen from lungs to tissues and carbon dioxide from tissues to lungs.
(ii) Chlorophyll . A green pigment present in green plants and algae is a coordination complex containing ` Mg^(2+) ` as central metal ion surrounded by a modified Porphyrin ligand called corrin ring . It plays an important role in Photosynthesis , by which plants converts `CO_2` and water into carbohydrates and oxygen.
(iii)Vitamin `B_(12) ` (cyancobalamine )is the only vitamin consist of metal ion . it is a coordination complex in which the central metal ion is ` CO^(+) ` surrounded by Porphyrin like ligand
(iv) Many enzymes are known to be metal complexes they regulate biological processes .For example , Carboxypeptidase is a protease enzyme that hydrolytic enzyme important in digestion . contains a zinc ion coordinated to the protein.