Final answer:
An antibody is a glycoprotein that recognizes and neutralizes foreign substances in the body. Its structure consists of four protein chains held together by disulfide bonds, forming a Y-shaped structure. The variable regions of the heavy and light chains are responsible for antigen recognition.
Step-by-step explanation:
An antibody, also known as an immunoglobulin, is a glycoprotein that plays a crucial role in the immune response, specifically in recognizing and neutralizing foreign substances in the body .The structure of an antibody monomer consists of four protein chains held together by disulfide bonds. It forms a Y-shaped structure, with two identical heavy chains and two identical light chains. The heavy chains make up the stem of the Y and have variable and constant regions, while the light chains make up the arms of the Y and also have variable and constant regions .The variable regions of the heavy and light chains are responsible for antigen recognition, while the constant regions provide structural stability and determine the class of the antibody.