What is the Difference Between Immunoglobulin and Antibody?

Immunoglobulins and antibodies are glycoprotein molecules produced by plasma cells (white blood cells) that play a crucial role in the immune response by specifically recognizing and binding to antigens, such as bacteria or viruses, and aiding in their destruction. Although the terms "immunoglobulin" and "antibody" are often used interchangeably, there are some differences between them:

1. Form: Immunoglobulins can occur in two main forms: soluble antibodies (which circulate freely in the bloodstream) and membrane-bound antibodies (which are attached to the surface of B cells). Antibodies refer to the soluble glycoproteins produced by B cells in response to a specific antigen.
2. Structure: Immunoglobulins have a transmembrane domain that enables the molecule to be attached to the plasma membrane of a B cell. Antibodies do not have transmembrane domains and are found freely in circulation.
3. Classes: There are five categories of immunoglobulins based on the type of heavy chain present in the molecule: IgG, IgA, IgM, IgD, and IgE. Each class of immunoglobulins produces different antibodies, and each antibody is specific to a particular pathogen.
4. Function: Surface immunoglobulins help B cells recognize the presence of a specific antigen in the body and stimulate the appropriate B cell activation. Secreted immunoglobulins assist in identifying and destroying invading pathogens such as viruses and bacteria.

In summary, immunoglobulins and antibodies are both involved in the immune response, but they differ in their form, structure, classes, and functions. Immunoglobulins can be either soluble antibodies or membrane-bound antibodies, while antibodies are soluble glycoproteins without transmembrane domains.

Comparative Table: Immunoglobulin vs Antibody

Immunoglobulins, also known as antibodies, are glycoprotein molecules produced by plasma cells or white blood cells. They specifically recognize and bind to particular antigens. Here is a table comparing the differences between immunoglobulins and antibodies:

In summary, immunoglobulins and antibodies are both involved in the immune response, but immunoglobulins encompass a broader range of functions, while antibodies specifically bind to antigens.