Isotype

Definition

An isotype refers to the different classes of antibodies (IgA, IgD, IgE, IgG, and IgM) found in all individuals of a species. These classes are determined by the constant region of the heavy chain in the antibody structure.

5 Must Know Facts For Your Next Test

1. Isotypes vary in their heavy chain constant regions which define their functional properties.
2. Human antibodies have five main isotypes: IgA, IgD, IgE, IgG, and IgM.
3. Each isotype has a distinct role in immune responses; for instance, IgG is crucial for opsonization.
4. Isotypes can be involved in different immune functions such as neutralization of pathogens or activation of complement systems.
5. The distribution and function of antibody isotypes can affect how effectively an immune response combats pathogens.

Review Questions

• What determines the class or isotype of an antibody?
• List the five main human antibody isotypes and one key function for each.
• How do differences in heavy chain constant regions influence antibody function?

Related terms

Antibody:

A protein produced by B cells that binds to specific antigens to neutralize them.

Epitope:

The specific part of an antigen that an antibody binds to.

B cell: A type of white blood cell that produces antibodies as part of the adaptive immune response.