The chemical reactions thus require enzymes to speed up their reaction. Most of the enzymes require metallic entities to help them function to their full capacity. Metallic ions like Zinc and Magnesium provide biological enzymes with good acid capability. Thus, the enzymes that are used for acid base reactions use magnesium and zinc at their active centers. In addition, inorganic compounds like sodium and potassium are required by living organism to create a potential difference across cell membrane. Unequal distribution of sodium and potassium ions across cell membrane help initiate an action potential.
Hemoglobin is an iron containing oxygen transport metalloprotein that is found in the red blood cells of vertebras (Anthea, Human Biology And Health). Its structure exhibits characteristics of both quaternary and tertiary structures of protein (Kessel, 122 Print). Most amino acids present in the hemoglobin are alpha helices and are joined together by non-helical structures. Hydrogen bonds present in the helical structure stabilize the helical units and give hemoglobin molecule its specific shape (Hemoglobin Tutorial, University of Massachusetts Amherst) The hemoglobin molecule has a protein part globin to which a small iron containing group heme. The heme consists of a charged iron ion that is contained in a heterocyclic ring. This heterocyclic ring is known as porphyrin and it consists of four pyrrole molecules linked together with iron bound in the center (Hemoglobin-School of Chemistry, Bristol University, ). The iron ion is the oxygen-binding site of hemoglobin. The iron ion coordinates with four molecules of nitrogen. The iron ion is strongly bound to the protein via imidazole ring of the F8 histidine residue below porphyrin ring. A sixth position bind oxygen reversibly by coordinate bond to complete the octahedral group of six ligands (Wiki Premed,