Question

list the 5 major classes of antibodies (immunoglobulins), explain the structure of each, and state a role that each plays in the immune system.

Answer 1

Antibodies have two basic functions: acting as the B cell antigen receptor or being secreted to bind pathogens. IgM and IgD are the only antibody classes that can function as antigen receptors for naive B cells.

Step-by-step explanation:

Five Classes of Antibodies and their Functions:

Humans possess five major classes of antibodies: IgM, IgD, IgG, IgA, and IgE, each with distinct structures and roles in the immune system. In general, antibodies have two basic functions. They can act as the B cell antigen receptor or they can be secreted, circulate, and bind to a pathogen, often labeling it for identification by other forms of the immune response.

Of the five antibody classes, notice that only two can function as the antigen receptor for naïve B cells: IgM and IgD. Mature B cells that leave the bone marrow express both IgM and IgD, but both antibodies have the same antigen specificity. Only IgM is secreted, however, and no other nonreceptor function for IgD has been discovered.