Adult hemoglobin

Adult Hemoglobin is a type of hemoglobin found in the red blood cells of adults and children over the age of six months. It is composed of two alpha and two beta chains, denoted as α2β2.

Structure

Adult hemoglobin, also known as Hemoglobin A (HbA), is a tetramer with a molecular weight of approximately 64,500 Daltons. Each of the four polypeptide chains in the molecule is attached to a heme group, a complex ring structure with an iron atom at its center. The iron atom is capable of binding one molecule of oxygen, allowing the hemoglobin molecule to carry up to four molecules of oxygen.

Function

The primary function of adult hemoglobin is to transport oxygen from the lungs to the tissues of the body, and to carry carbon dioxide, a waste product of cellular metabolism, back to the lungs to be exhaled. The ability of hemoglobin to bind and release oxygen is regulated by several factors, including the partial pressure of oxygen, the pH of the blood, and the concentration of certain metabolites such as 2,3-bisphosphoglycerate.

Disorders

Abnormalities in the structure or function of adult hemoglobin can lead to a variety of hemoglobinopathies, including sickle cell disease and thalassemia. These disorders are typically caused by mutations in the genes that encode the alpha or beta chains of the hemoglobin molecule.

See also

• Hemoglobin
• Heme
• Oxygen transport
• Hemoglobinopathy
• Sickle cell disease
• Thalassemia