EVERYDAY SCIENCE

Detailed explanation-1: -The heme group (a component of the hemoglobin protein) is a metal complex, with iron as the central metal atom, that can bind or release molecular oxygen.

Detailed explanation-2: -The hemoglobin molecule contains four separate folded peptide chains, which form a hydrophobic or water ‘repelling’ pocket around a heme group. The heme group is composed of a central iron atom complexed to four nitrogen atoms.

Detailed explanation-3: -The answer is C. Fe3+. Hemoglobin consists of four subunits, each with an iron molecule that can bind one oxygen molecule. Iron in hemoglobin is usually in the 2+ state, but a small percentage (<1%) is in the oxidized state (3+).

Detailed explanation-4: -The following statement was made: “So far as the literature shows, hemoglobin does not contain copper.” The presence of copper in blood has been reported by a few workers. McHargue (2) reported a variation of 1 to 4 mg. of copper per kilo of fresh blood taken from several different animals.

Detailed explanation-5: -Each hemoglobin molecule is made up of four heme groups surrounding a globin group, forming a tetrahedral structure. Heme, which accounts for only 4 percent of the weight of the molecule, is composed of a ringlike organic compound known as a porphyrin to which an iron atom is attached.