Antibody

Definition

Antibodies are Y-shaped proteins produced by B cells in response to specific antigens. They play a crucial role in the immune system by identifying and neutralizing pathogens like bacteria and viruses.

5 Must Know Facts For Your Next Test

1. Antibodies are also known as immunoglobulins (Ig) and come in five main classes: IgA, IgD, IgE, IgG, and IgM.
2. The variable region of an antibody binds specifically to an antigen, while the constant region determines its class and function.
3. B cells must be activated by helper T cells before they can produce antibodies.
4. Monoclonal antibodies are laboratory-produced molecules engineered to serve as substitute antibodies that can restore, enhance, or mimic the immune system's attack on cells.
5. Vaccines stimulate the production of antibodies without causing disease.

Review Questions

• What are the main functions of antibodies in the immune system?
• How do B cells become activated to produce antibodies?
• Name and briefly describe the five classes of immunoglobulins.

Related terms

Antigen: A molecule or molecular structure that is recognized by an antibody as foreign, triggering an immune response.

B Cell: A type of white blood cell that produces antibodies in response to antigens.

Helper T Cell: A type of T cell that assists other white blood cells in immunologic processes, including activating B cells to produce antibodies.