Answer:
Hemoglobin has a critical role in the body, as it is the protein in red blood cells (RBCs) that carries oxygen from the lungs to the tissues of the body. As such, abnormal levels of hemoglobin, or abnormal types of hemoglobin can result in serious disease. Let's look at the normal ranges of hemoglobin in adults in children, conditions that cause either a low hemoglobin or a high hemoglobin level, and the tests for and significance of hereditary abnormal hemoglobins
Structure
Hemoglobin is protein in red blood cells that is made up of four chains. Each of these chains contains a compound known as heme, which in turn contains iron, which is what transports oxygen in the bloodstream.
Hemoglobin is responsible for the shape of red blood cells, which usually appear like donuts but with a thin center rather than a hole. In conditions in which hemoglobin is abnormal, such as sickle cell anemia, the consequent abnormal shape of the red blood cells can lead to problems.
The pigment in hemoglobin is responsible for the red color of blood.
Function
Hemoglobin functions by binding and transporting oxygen from the capillaries in the lungs to all of the tissues in the body. It also plays a role in the transport of carbon dioxide from the tissues of the body back to the lungs.
Nitric oxide and carbon monoxide are also able to bind with hemoglobin, with carbon monoxide binding much more readily than oxygen (the reason why carbon monoxide poisoning is so serious).