What Is The Difference between IgM and IgG?

What is the difference between  IgM and IgG? The main difference between IgG and IgM is that IgG represents the late stage response to a disease whereas IgM is produced immediately after the exposure to a particular antigen. 

The immune system creates antibodies to safeguard the body from viruses, bacteria, and allergens. It produces specific antibodies, known as immunoglobulins, to counter different substances. Immunoglobulin is those proteins that tend to bind antigen in a specific case. These immunoglobulins are also known as antibodies.

Both IgM and IgG belong to the immunoglobulin class. They are known to play a vital role in the body of both animals and human beings. The lesson provides the differences and similarities between IgM and IgG. Take the time to also explore the meaning and how they work in the body.

Difference between IgM and IgG

Difference between IgM and IgG With Table

Basic Terms IgM IgG
Where they are Located Lymph fluids and blood Intestines, blood, and lymph
Produced by Plasma cells White blood cells
Role The first antibody developed due to response of antigen or foreign materials in the body Produce when in need of secondary immune towards long term infection.
Size Pentamer with Y-shaped units joint together by the polypeptide chain Monomer with a Y-shaped unit.
Number of Antigen binding 10 2
Types Has no classification It has four classes such as IgG1, IgG2, IgG3, IgG4.
Molecular weight 900,000MW 150,000MW
Light chains kappa (κ ) and lambda ( λ). kappa (κ ) and lambda ( λ).
Heavy chains mu (µ). gamma (γ ).
Amount presence in serum 10 percent 75 percent
High amount effect It causes parasitic infections, kidney damage, rheumatoid arthritis, hepatitis, mononucleosis. Imply the presence of long term infection to HIV, multiple myeloma, multiple sclerosis.
Low amount effect It causes leukemia and a few inherited diseases. It causes kidney damage and other types of infection.
Amount of carbohydrate present 12 percent 3 percent

What Is Immunoglobulin M (IgM)?

IgM is those antibodies produced in response to exposure to antigens or foreign materials in the body. They are particularly large in amount.

These antibodies are quite common in blood and lymph. They are developed in the plasma cells. They are known to be quite effective when it comes to evading viruses, bacteria, and other pathogens.

Research shows that IgM is normally the first antibody present in the human fetus. It has a Y-shape pentamer joint together by a polypeptide chain.

IgM is temporal and they tend to have a short lifespan of about 2-3 weeks in the body. Excessive accumulation of IgM could result in parasitic infection, mononucleosis, kidney damage, and rheumatoid arthritis.

On the other hand, an insufficient supply of IgM in the blood could result in myeloma, leukemia, and other inherited diseases.

What Is Immunoglobulin G (IgG)?

IgG are those antibodies that protect the body against bacterial or viral infection. They are produced by white blood cells hence occur in abundance in the body. They are quite common in blood serum. Also, regarded to be the smallest in amount when compared to IgM.

They occur in the monomer unit of Y-shape. It has two antigen-binding sites and a heavy chain of gamma. This is the only antibody that can travel via blood and transferred from the mother placenta to the developing embryo in the womb.

Lastly, these antibodies are produced when there is a need for a secondary immune response towards antigen, phagocytosis, getting rid of viruses or bacteria, and promoting opsonization.

Having a high amount of IgG is due to long term infection like multiple myeloma, HIV, and multiple sclerosis. A low amount of IgG can result in kidney damage and other few infections in the body.

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Main Differences between IgM and IgG 

  1. IgM provides immediate response when exposed to antigens or foreign materials while IgG provides secondary immunity to long term infections.
  2. IgM has a pentamer unit with ten antigen-binding sites while IgG has a monomer unit with two antigen-binding sites.
  3. IgM is the first antibody produced in the human fetus and cannot pass into the placenta due to a large size while IgG can be transferred from the mother to the developing embryo via the placenta.
  4. IgM is produced in the plasma cells and found in lymph fluid and blood while IgG produced by white blood cells and presence in intestines, blood, and lymph.
  5. IgG has four different types such as IgG1, IgG2, IgG3, and IgG4 while IgM has no type.
  6. IgG has a heavy chain of gamma (γ) while IgM has a heavy chain of mu (µ).
  7. IgG has a percentage of 75 in serum while IgM has a percentage of 10.
  8. The molecular weight of IgG is 150,000MW while that of IgM is 900,000MW.

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Antibodies are protein in nature and they are produced by B-lymphocytes. The main aim of antibodies is to offer defense and fight off infections in the body. There are about five types of antibodies where IgM and IgG are part of the types. All these antibodies vary in size and weight.

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