Of the fourglobins that make up hemoglobin, two are identical and called alpha globins, and the other two are called beta globins and are also identical.
<h3>Structure of Haemoglobin</h3>
Each of the four subunits of hemoglobin has a polypeptide chain and a heme group.
The iron protoporphyrin IX prosthetic heme group, which is connected to a polypeptide chain with residues of 141 (alpha) and 146 (beta) amino acids, is present in all hemoglobins.
A histidine's N is linked to the ferrous iron of the heme. A polypeptide chain phenylalanine of the porphyrin ring wedges it into its pocket.
Alpha and beta chains, two varieties of the polypeptide chains that make up adult hemoglobin, are comparable in length but have different amino acid sequences.
Both adult and embryonic human hemoglobins have the same alpha chain.
The flow of individuals in and out of a populationintroduces new alleles and increases genetic variationwithin that population. Mutations are changes to an organism's DNA that create diversity within a population by introducing new alleles.