Ans.
Opsonization is defined as an immune reaction that includes ingestion and elimination of a pathogens by phagocytes, with the help of antibodies and complement proteins.
The antibodies involve in opsonization are mainly IgG (gamma immunoglobulins). The IgG binds with pathogen via its Fab (antigen-binding fragment) domain and opsonizes it. The antibody-pathogen complex then binds with an immune cell via Fc (fragment of crystallization) domain of IgG antibody that triggers secretion of lytic proteins from immune cell to kill the pathogen.
Thus, 'opsonization is a representative of IgG antibody function.'
