What Is The Role Of Haemoglobin?

red blood cells

What’s covered?

If you think that the primary function of haemoglobin is to carry oxygen and carbon dioxide molecules, then you are wrong. It does play a vital role in transporting these gases in red blood cells, particularly its oxygen carrying capacity. Still, it also creates a sticky environment that helps to stiffen the red blood cells so that they cannot change shape easily as haemoglobin molecules do not let the red blood cells lose their original form and make them not flexible enough. Basically, without the presence of haemoglobin, red blood cells would be squishy. They would lose their shape, making it more difficult to pass through small capillaries.


The blood separation, release, storage, and transport of oxygen are expressed through the oxygen-dissociation curve. Acute haemolytic physiology is determined by oxygen affinity, which determines 50% - saturation p50 - The oxygen-dissociations curve for normal haemoglobin is derived from the reaction between haemoglobin and oxygen modified by hydrogen ions (Bohr effects) and 2,3-bisphosphoglycerates (30, 31). Haemoglobin oxygen affinity increases as temperatures decrease and decreases as pH increases. Therefore, due to the vascular structure, red blood cells containing such abnormal haemoglobin may have an abnormal oxygen-dissociation curve.

How does oxygen binding capacity affect haemoglobin?

The dissociation curve moves to the left as a result of the binding of one oxygen molecule to haemoglobin. This causes the affinity of the other binding places on haemoglobin for oxygen to rise. Because of this shift, oxygen cannot be unloaded from the peripheral tissue, and as a result, the oxygen concentration in the tissue is significantly lower than it would normally be.

For more information and our comprehensive guide to blood tests, click here.


Iron atoms must be ferrous and attached together for haemoglobin as it binds oxygen. When oxidation occurs in the haemoglobin molecule, ferrous iron will convert to iron ferric iron, and methaemoglobin will form. Methaemoglobin is unremarkable respiratory pigment. Almost all blood derived from circulating haemoglobin is converted to methemoglobin each day. The iron itself is anchored in the "hème pocket" to the amino acids histidines – the proximal histidine. The histidine is also located outside this pocket. This second histidine does not have direct contact with the ferric material and is called distal histidine.

How does Haemoglobin affect oxygen saturation?

The amount of oxygen molecules that are carried by the blood is determined by the haemoglobin content. In people who have anaemia, the delivery of oxygen molecules is reduced while the extraction of oxygen is enhanced. This results in a drop in the tissue oxygen saturation as well as a decrease in the venous haemoglobin saturation, thus, resulting in deoxygenated haemoglobin.

Haemoglobin, a protein found in normal red blood cells, is essential in oxygen transport. If you have a low haemoglobin molecule, it might result in iron deficiency anaemia that will make you feel tired and weak. Normal adult haemoglobin is composed of two alpha chains and two β subunits of beta chains. Abnormal haemoglobins indicate anaemia and are found in sickle cell disease.

The Haemoglobin concentration and human body

Your haemoglobin concentration is an important indicator of the health of your blood. Your haemoglobin protein is made up of four amino acids: valine, glutamic acid, cysteine and histidine. The sequence of these amino acids determines how your body will make use of them.

The human body requires a specific type of haemoglobin molecule that transports oxygen in the blood.

hemoglobin gene


Haemoglobin consists of four parts, one of which carries one heme group and one polypeptide. The haemoglobins have the same prothetic Hema group iron protoporphyrin IX and 141 (alpha) and 146 (beta) amino acids. Ferrous ions are connected to histidine N in the heme. Porphyrin rings are embedded in the polypeptide chain phenylalanine. These polypeptide chains are derived from adult haemoglobin and are of two different kinds: Alpha-Beta Chain. All humans are made up of an Alpha chain.

What are the three functions of haemoglobin?

To sum it up, haemoglobin is tasked with transporting oxygen. It also provides red colour to the red blood cell. Haemoglobin is also responsible for maintaining the red blood cells' shapes. It also transports carbon dioxide.


Haemoglobin is a protein in red blood cells that transports oxygen into the body. The lack of haemoglobin causes fatigue, as well as a rapid heartbeat. A high haemoglobin level may cause a lot of medical problems. In conditions such as sickle cell anaemia, haemoglobin has abnormalities. It may cause serious health issues, such as blood loss and bleeding. Generally, haemoglobin levels are measured in a blood sample. Some tests may help diagnose anaemia.

For a full range of medications, visit our Welzo Online Pharmacy Page. For more information about your blood count and the cells in your body order our Full Blood Count Test.

Share article
1 of 4
1 of 4
Get 10% off your first order

Plus get the inside scoop on our latest content and updates in our monthly newsletter.