EVERYDAY SCIENCE

Detailed explanation-1: -The hemoglobin molecule is made up of four polypeptide chains (Alpha 1, Beta 1, Alpha 2, Beta 2), noncovalently bound to each other. There are four heme-iron complexes. Each chain holds a heme group containing one Fe++ atom. The heme-iron complexes are colored red because they give hemoglobin its red color.

Detailed explanation-2: -Hemoglobin comprises four subunits, each having one polypeptide chain and one heme group (Figure 1). All hemoglobins carry the same prosthetic heme group iron protoporphyrin IX associated with a polypeptide chain of 141 (alpha) and 146 (beta) amino acid residues.

Detailed explanation-3: -Four heme groups containing iron atoms are attached with four globular proteins from the hemoglobin molecule. The iron atom is present in +2 oxidation state in deoxyhemoglobin and +3 oxidation state in oxyhemoglobin.

Detailed explanation-4: -Many different types of hemoglobin (Hb) exist. The most common ones are HbA, HbA2, HbE, HbF, HbS, HbC, HbH, and HbM. Healthy adults only have significant levels of only HbA and HbA2. Some people may also have small amounts of HbF.