Now how exactly does the binding process between an antibody and an antigen actually take place? Well, in our body we have five categories of antibodies and antibodies are also known as immunoglobulins. And that's because immuno means it's part of our immune system and globulin means the spherical shape, the globelike shape of that particular antibody. So immunoglobulin g is one of the five different categories of antibodies that we have inside our body. And the shape of immunoglobulin g is shown here. So immunoglobulin g consists of four polypeptide chains.