Blood is considered the fluid connective tissue of the human body. Blood consists of plasma and blood cells. Plasma is the liquid component and different types of blood cells are suspended in it.
RBC, WBC, and Platelets are the different types of blood cells. Each blood cell has a peculiar function.
RBC vs Hemoglobin
The difference between RBC and Hemoglobin is that RBCs are a type of blood cells while hemoglobin is the red pigment present in RBC. RBCs are produced in the bone marrow and circulate in the blood. Hemoglobin is the protein pigment that gives blood its red color.
Want to save this article for later? Click the heart in the bottom right corner to save to your own articles box!
RBC is also known as Red blood corpuscles or erythrocytes. They are the common type of blood cell in vertebrates. Their main function is to supply oxygen to all the body cells.
The oxygen molecules entering the lungs through respiration are taken up by the RBCs and are transported to different parts of the body through circulation.
Hemoglobin is a protein in the red blood cells. It helps the RBC in carrying oxygen and carbon dioxide. Hemoglobin is a metalloprotein. It has Iron and globin.
It gives RBC and blood its red color. Hemoglobin is a red-colored pigment. There are many other pigments like hemoglobin that are present in some invertebrates.
Comparison Table
| Parameters of Comparison | RBC | Hemoglobin |
|---|---|---|
| Structure | Biconcave, disk-shaped | Consists of four subunits with four polypeptide chains each attached to one heme group. |
| Location | RBC is present in the blood | Hemoglobin is present in the RBC |
| Normal range | 4.7-6.1 million cells per microliter for men and 4.2-5.4 million per microliter for women | 14-18 g per deciliter for men and 12-15 grams per deciliter for women. |
| Category | Blood cell | Red pigment protein |
| Main Function | Transports hemoglobin bound to respiratory gases and supply oxygen to the body tissues | Binding to respiratory gases |
| Other functions | Releases free radicals and lyse pathogen | Functions as antioxidant and regulate iron metabolism |
What is RBC?
Red blood corpuscles are enucleated, oval, or biconcave disk-shaped structures. They are formed and matured in the bone marrow. Their lifespan is 100-120 days.
They lack a nucleus as they make space to accommodate the red pigment hemoglobin. 2.4 million new RBCs are produced every second in humans.
They make up 40-45% of the total volume of blood.
The cell membrane of RBC is permeable for oxygen molecules. Oxygen enters RBC through diffusion. It then travels in the blood to different body parts and enters the cells.
Human RBC has a diameter of 6.2-8.2µm. Women have 4-5 million RBC per microliter of blood while, men have 5-6 million RBC per microliter of blood.
Their major function is to transport oxygen. During stressful conditions, RBCs release ATP which leads to the relaxation of blood vessels which eventually leads to normal blood flow.
They also have some immunological functions. When attacked by a pathogen they release free radicals to lyse the cell wall of the pathogen and kill it.
Having a normal RBC count is healthy. An increase or decrease in the number of RBC may cause certain diseases. A decrease in the number of RBC leads to a condition called Anemia.
Anemia may be caused by Vitamin B12 or folate deficiency, stomach ulcer, or excessive blood loss. An increase in the number of RBC causes Polycythemia.
What is Hemoglobin?
Hemoglobin is the protein pigment present in RBC. It is made up of four amino acid chains. A heme group is attached to each of these chains.
The heme group is made up of a porphyrin ring and an iron atom. Each hemoglobin molecule can carry four oxygen atoms.
The iron atoms temporarily bind with the oxygen atoms. This binding is temporary and on reaching the target cells oxygen dissociates and enters the cells.
Hemoglobin also carries back a small amount of carbon dioxide which is the waste product of cellular respiration.
Hemoglobin also causes changes in blood color. When hemoglobin combines with oxygen forming Oxyhemoglobin, the blood is scarlet or bright red.
When the oxygen is released deoxyhemoglobin is formed which gives the blood a dark burgundy color. Hemoglobin also combines with carbon monoxide forming carboxyhemoglobin.
Hemoglobin is responsible for the transportation of 98% of the total oxygen in humans.
The hemoglobin content of a healthy individual is 12-14 g per 100ml of blood. Hemoglobin makes up 96% of the total weight of RBC.
Hemoglobin is also present in other body parts like macrophages, alveolar cells, lungs, hepatocytes, retinal pigment, etc and functions as an antioxidant and iron metabolism regulator.
Main Differences Between RBC and Hemoglobin
- RBCs are blood cells involved in oxygen transportation. Whereas, hemoglobin is the pigment present in RBC which binds with oxygen and is responsible for oxygen transportation by RBC.
- RBC is biconcave, disc-shaped, enucleated blood cells produced in the bone marrow. While hemoglobin is a metalloprotein made up of globin and heme.
- An increase in RBC causes Polycythemia while increase in hemoglobin causes hemoglobinemia.
- A decrease in RBC causes a condition called anemia characterized by fatigue and pale skin. A decrease in hemoglobin leads to thalassemia, engagement of spleen, vasculitis, and anemia by lowering the RBC’s ability to carry oxygen.
- The main function of hemoglobin is to bind with respiratory gases and hold them. But, RBC has a major function of transporting the gases bound to hemoglobin to different parts of the body through blood.
- https://onlinelibrary.wiley.com/doi/abs/10.1002/ajh.25937
- https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1525-1594.2004.07394.x
I’ve put so much effort writing this blog post to provide value to you. It’ll be very helpful for me, if you consider sharing it on social media or with your friends/family. SHARING IS ♥️
Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.
