Final answer:
Opsonization is a process where antibodies coat pathogens to enhance their recognition and destruction by phagocytic cells. Complement fixation further boosts this mechanism, leading to swift pathogen clearance, with IgG playing a pivotal role by providing binding sites for phagocytes.
Step-by-step explanation:
The enhancement of phagocytosis due to the deposition of an antibody on the surface of a pathogen or antigen is called opsonization. This biological process involves antibodies marking pathogens for destruction by phagocytic cells such as macrophages or neutrophils. When antibodies bind to antigens on the pathogen's surface, they act as opsonins — facilitators for phagocytic cells to recognize, bind, and engulf pathogens more efficiently.
Furthermore, certain antibodies can initiate a complement fixation, where they bind to antigens and provide docking sites for complement proteins. This synergistic action of antibodies and complement significantly improves the efficacy of opsonization and leads to the rapid clearing of pathogens from the host organism. IgG molecules, in particular, have a critical role in opsonization by providing their Fc regions as binding sites for phagocytes, strengthening the attachment and ingestion process of the pathogens.