The binding of an antigen to the human B Cell receptor is identical to other common soluble antibodies (such as [https://en.wikipedia.org/wiki/Immunoglobulin_G IgG], [https://en.wikipedia.org/wiki/Immunoglobulin_A IgA], [https://en.wikipedia.org/wiki/Immunoglobulin_M IgM], [https://en.wikipedia.org/wiki/Immunoglobulin_E IgE], or [https://en.wikipedia.org/wiki/Immunoglobulin_D IgD]). The antibody portion of the B Cell Receptor is roughly "Y" shaped and consists of two identical <scene name='95/952701/Heavy_chains_highlight/1'>heavy</scene> and two identical <scene name='95/952701/Light_chains_highlight/1'>light</scene> chains creating two similar epitope or binding regions. Thus, two antigen molecules can bind independent of one another to produce a response. Within this structure, there are both constant and variable regions. The stem of the "Y" is a constant region ([https://en.wikipedia.org/wiki/Antibody#CDRs,_Fv,_Fab_and_Fc_Regions Fc]) composed of only heavy chain interactions. The two heavy chains then branch at a flexible hinge region. These interact individually with one light chain creating two [https://en.wikipedia.org/wiki/Antibody#CDRs,_Fv,_Fab_and_Fc_Regions Fab] fragments or branches of the "Y". Each Fab fragment additionally contains a variable region ([https://en.wikipedia.org/wiki/Antibody#CDRs,_Fv,_Fab_and_Fc_Regions Fv]) and a constant region. The variable region sits on top of the constant region and consists of hyper-variable loops which are random coils of amino acids that are unique to an antibody and exposed to allow specific recognition of an antigen. Furthermore, the light chains interact with the heavy chains via weak intermolecular forces and disulfide bridges. Therefore, binding to an antigen is processed through intermolecular interactions and is specific due to unique hyper variable loops.