Question

Draw only labelled diagram of a single antibody molecule.

Hint:

Antibodies are highly specific proteins that bind to antigens. The diversity in antibodies is created by the variability in the antigen-binding sites.

Answer 1

An antibody molecule, also known as an immunoglobulin (Ig), consists of four polypeptide chains: two heavy chains (H) and two light chains (L). The structure of an antibody is typically Y-shaped, with the arms of the Y representing the antigen-binding sites. The main parts of an antibody are: \begin{enumerate} \item Antigen-binding site: The part of the antibody that binds to a specific antigen. This is located at the tips of the Y-shaped structure. \item Variable region: The portion of the antibody that varies to recognize different antigens. \item Constant region: The region that is identical for all antibodies of the same class. It determines the mechanism used to destroy the antigen. \item Heavy chains (H): The larger polypeptide chains that form the base of the Y and contribute to the constant region. \item Light chains (L): The smaller polypeptide chains attached to the heavy chains that form the arms of the Y. \item Fc region: The tail of the Y-shaped antibody that binds to receptors on immune cells. \end{enumerate}