Hemoglobin molecule

The hemoglobin is the intensely colored pigment which imparts the red color o the blood; hemoglobin is the most abundant blood protein in man, and represents more than 95% of the soluble protein content of the erythrocytes.

The hemoglobin molecule is composed of two parts, heme and globin, The globin portion of a hemoglobin molecule contains four proteins, two α-chains, and two β-chains. Both the α- and β-chains of hemoglobin are very similar to the myoglobin chain. The α -chain is 141 residues long, and the β -chain is 146 residues long: for comparison, the myoglobin chain is 153 residues long.

The heme portion of hemoglobin molecules contains iron. Iron makes up 0.35% of the hemoglobin molecule and its porphyrin moiety an additional 3,5% with the remainder consisting of protein.

Each of hemoglobin has a molecular weight of approximately 64,000 and an elliptical shape with molecular dimensions of approximately 63 x 55 x 50 A. Hemoglobin molecules continually release and bind oxygen molecules as they travel through the circulatory systems. At areas of high levels of oxygen concentration, the hemoglobin molecules reabsorb the oxygen they release.
Hemoglobin molecule