There are 5 different classes of antibodies: IgG, IgM, IgD, IgE and IgA. What makes them different from each other are the amino acid sequences present in the Fc region of the heavy chain. Because effector function relies on amino acid sequences in the Fc region, some of the functions they provide are class-specific. In total, there are 4 major effector functions of antibodies: neutralization of microorganisms and toxins, antibody-mediated opsonization and phagocytosis of microorganisms, antibody-dependent cellular cytotoxicity, and activation of the complement pathway. Neutralization of microorganisms occurs when antibodies bind to microorganisms, preventing them from interacting with the cell surface receptor. By binding to microorganisms, it also prevents the spread of infection from cell to cell. Neutralization of toxins is completed by antibodies that block microorganism toxins by binding to cell surface receptors. This then inactivates the harmful effects of the toxins. The same goes for virus neutralization where antibodies bind to the virus and prevent it from attacking...