Difference Between Normal Red Blood Cell and Sickle Cell

The key difference between normal red blood cell and sickle cell is that normal red blood cells are round in shape, while sickle cells are distorted red blood cells having a sickle shape.

Red blood cells are a major component in our blood. These cells carry oxygen throughout our body. They also transport and remove carbon dioxide from our body. Sickle cell anaemia is a type of anaemia owing to the presence of abnormal shaped red blood cells. The condition occurs primarily due to a genetic defect. Hence, it is important to diagnose sickle cell anaemia early in life to prevent mortality.

CONTENTS

1. Overview and Key Difference
2. What is a Normal Red Blood Cell 
3. What is a Sickle Cell
4. Similarities Between Normal Red Blood Cell and Sickle Cell
5. Side by Side Comparison – Normal Red Blood Cell vs Sickle Cell in Tabular Form
6. Summary

What is a Normal Red Blood Cell?

Red blood cells or erythrocytes are a type of blood cells in the human body. Bone marrow is the site of red blood cell production. They are flat cells, which are round in shape. They appear as oval biconcave disks. Moreover, they do not possess a nucleus or most cell organelles, especially mitochondria. Therefore, they depend on anaerobic respiration for survival.

Haemoglobin is a major constituent of red blood cells. The characteristic red colour of blood is due to the presence of haemoglobin in normal red blood cells. The main function of normal red blood cells is to transport oxygen and carbon dioxide in the body. They bind to oxygen via oxyhemoglobin and carbon dioxide via carbhemoglobin. In this regard, red blood cells facilitate the transport of respiratory gases in the body. Additionally, a low red blood cell count signifies anaemic conditions, metabolic disorders or malnutrition.

What is a Sickle Cell?

Sickle cell anaemia is an inherited disease condition that arises due to the formation of abnormal shaped red blood cells called sickle cells. As its name implies, sickle cells have a sickle shape. Thus, sickle cells are defective. Furthermore, sickle cells are composed of Hemoglobin S in comparison to the normal type Hemoglobin A. The presence of abnormal Hemoglobin S causes the abnormal shape of sickle cells. Therefore, with time, the sickle cells convert to cells that are more rigid and sticky. Due to this abnormal shape of the red blood cells, they can get stuck in small blood vessels, slowing and blocking the blood flow. Thus, our body parts will not receive sufficient amounts of oxygen, causing fatigue.

The outcomes of sickle-shaped red blood cells lead to sickle cell anaemia. They are:

• Clogging of blood vessels may lead to the pain of organs that lack blood supply.
• Reduction of oxygenated haemoglobin for transport.
• The high rate of destruction by the spleen. It leads to the reduction of the red blood cells leading to anaemia.

Furthermore, sickle cell anaemia can lead to several complications, including stroke, acute chest syndrome, pulmonary hypertension, organ damage and blindness.

What are the Similarities Between Normal Red Blood cell and Sickle Cell?

• Both are types of red blood cells.
• Moreover, they carry oxygen bound to haemoglobin.
• They lack nuclei and mitochondria.
• Both perform anaerobic respiration.

What is the Difference Between Normal Red Blood cell and Sickle Cell?

The key difference between normal red blood cell and sickle cell is the shape of the cell. That is; normal red cells are round in shape while the sickle cells have a sickle shape. Also, a further difference between normal red blood cell and sickle cell is that normal red blood cells are flexible while sickle cells are rigid and sticky.

Moreover, normal red cells contain haemoglobin A and sickle cells contain haemoglobin S. So, this is another difference between normal red blood cell and sickle cell.

The below infographic presents more information regarding the difference between normal red blood cell and sickle cell.

Summary – Normal Red Blood cell vs Sickle Cell

Red blood cells primarily carry oxygen and carbon dioxide in the blood bound to haemoglobin. However, conditions such as sickle cell anaemia give rise to abnormal shaped red blood cells which fail to perform their normal function. In this context, normal red blood cells refer to the normal red cells that are round in shape and contain haemoglobin A. In contrast, sickle cells refer to the abnormal red cells that are sickle-shaped and contain haemoglobin S. Therefore, this summarizes the difference between normal blood red cell and sickle cell.

Reference:

1. Gossman, William. “Anemia, Sickle Cell.” StatPearls [Internet]., U.S. National Library of Medicine, 12 July 2019, Available here.

Image Courtesy:

1. “Red blood cell” By Database Center for Life Science (DBCLS) (CC BY 3.0) via Commons Wikimedia
2. “Sickle Cell Disease (27249799083)” By National Human Genome Research Institute (NHGRI) from Bethesda, MD, USA – Sickle Cell Disease (CC BY 2.0) via Commons Wikimedia