Biochemistry, Hemoglobin Synthesis.

Biochemistry, Hemoglobin Synthesis.

Farid Y; Bowman NS; Lecat P

StatPearls

2021

2021-01

Hemoglobin is an oxygen-binding protein found in erythrocytes that transports oxygen from the lungs to tissues. Each hemoglobin molecule is a tetramer made of four polypeptide globin chains. Each globin subunit contains a heme moiety formed of an organic protoporphyrin ring and a central iron ion in the ferrous state (Fe2+). The iron molecule in each heme moiety can bind and unbind oxygen, allowing for oxygen transport in the body. The most common type of hemoglobin in the adult is HbA, which comprises two alpha-globin and two beta-globin subunits. Different globin genes encode each type of globin subunit.[1] The two main components of hemoglobin synthesis are globin production and heme synthesis. Globin chain production occurs in the cytosol of erythrocytes and occurs by genetic transcription and translation. Many studies have shown that the presence of heme induces globin gene transcription. Genes for the alpha chain are on chromosome 16, and genes for the beta chain are on chromosome 11. Heme synthesis occurs in both the cytosol and the mitochondria of erythrocytes. It begins with glycine and succinyl coenzyme A and ends with the production of a protoporphyrin IX ring. The binding of the protoporphyrin to a Fe2+ ion forms the final heme molecule.[2]

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NEOMED College of Medicine

Department of Internal Medicine

NEOMED Student Publications

June 2021 List