HAEMOGLOBIN CHEMISTRY

HAEMOGLOBIN CHEMISTRY

Haemoglobin is the red pigment in  the body cells, that carries the oxygen from the lungs to the tissues.it is called the respiratory pigment. It delivers the oxygen from the lungs to the tissue.it is called respiratory pigment.It delivers the oxygen molecule to the myoglobin in the tissue.it is protein containing an iron- prophyrin complex.

                                           

                                     Fig.HAEMOGLOBIN

Haemoglobin in the red blood cells combines with inhaled oxygen in the lungs and transport it to the cell of the body.

STRUCTURAL FEATURES OF HAEMOGLOBIN

1.Haemoglobin consist of four subunits.

2. Each sub unit is folded chain which consist of a protein unit called globin and heme group and histidine unit.

3.heme unit is a chelate of iron with porphine ligand.

4. its molecular weight is about 65000.

5.the four polypeptide chains of haemoglobin are bound in such manner the the molecule is spherical.

6.The iron in the haemoglobin is in the fe(II) state.it is coordinate to the four nitrogen atoms in the porphine group.Two more ligands and the histidine unit and water molecule are also coordinate to fe(II).

7.The complex is octahedral.The prophyrin ring is conjugated and planer.

The arteries carry blood to the muscle in various parts of the body where oxygen is required.in muscle the oxygen is transferred to myoglobin molecule and stored until it is required produce energy from the glucose.when haemoglobin looses its oxygen a water molecule is again co-ordinate to iron. This indirectly helps to remove carbondioxide from the tissue carbondioxide is converted to bicarbonate.lastly bicarbonate is converted to carbondioxide and exhaled from the body.the oxygen carrying process by haemoglobin is reversible.