1. Name the primary classes of antibodies and describe their structures. IgM: IgG: IgA: IgD: IgE:

2. In response to an antigen, which antibodies are secreted/produced first? Are all classes of antibodies found in the circulation at all times?

1. There are five primary classes of antibodies, that are IgM, IgG, IgA, IgD, IgE.

2. IgM

Explanation:

The antibodies are proteins that are Y-shaped and are also called immunoglobulins. The antibody is produced when any pathogen attacks the body. There are five primary classes of antibodies, that are IgM, IgG, IgA, IgD, IgE. The antibody contains two heavy and two light chains. The IgM is a pentamer immunoglobulin. The IgG is contains two gamma heavy chains and two light chains. The IgA is mostly monomeric. The IgD have two delta heavy chains and light chains. The IgE contains two ∈ chains and light chains.

IgM is produced first. The IgA produced after IgM on mucosal surfaces. The IgG is present in serum. The all immunoglobulins IgM, IgA, IgD, IgE, and IgG are abundant in blood circulation.