Hemoglobin A3

Hemoglobin A3 (also known as HbA3) is a minor component of hemoglobin, the protein in red blood cells that carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues back to the lungs. Hemoglobin A3 is a variant of the major form of hemoglobin, known as Hemoglobin A1.

Structure

Hemoglobin A3, like other forms of hemoglobin, is a tetramer composed of two alpha and two beta chains. Each of these chains is attached to a heme group, a ring-like structure that contains an iron atom. This iron atom is what allows hemoglobin to bind to oxygen in the lungs and carry it to the tissues.

Function

The primary function of Hemoglobin A3, as with all forms of hemoglobin, is to transport oxygen from the lungs to the tissues of the body. It also helps to transport carbon dioxide, a waste product of cellular metabolism, from the tissues back to the lungs, where it can be exhaled.

Clinical significance

Hemoglobin A3 is a minor component of total hemoglobin, typically making up less than 1% of the total. However, its levels can be increased in certain conditions, such as diabetes and thalassemia, a group of genetic disorders that affect the body's ability to produce normal hemoglobin.

See also

• Hemoglobin A
• Hemoglobin A2
• Hemoglobinopathy