What are antibodies primarily composed of?

Antibodies are primarily composed of proteins. They are a type of immunoglobulin that plays a crucial role in the immune system by identifying and neutralizing foreign objects like bacteria and viruses. The structure of an antibody is complex, consisting of two heavy chains and two light chains, which form a Y-shaped molecule. These protein chains are held together by disulfide bonds, giving antibodies their distinctive shape that allows them to specifically bind to antigens, the substances they target.

Understanding that antibodies are proteins is fundamental to grasping how they function in the immune response. Protein composition is essential because the unique sequences of amino acids in the antibody structure determine its specificity and ability to recognize a wide variety of pathogens. This specificity is vital for the adaptive immune system, allowing it to remember and respond more effectively to previously encountered foreign substances.