What main function do antibodies serve in the immune system?

Antibodies primarily serve the essential function of identifying and neutralizing pathogens, such as bacteria and viruses, within the immune system. They are specialized proteins produced by B cells and play a crucial role in the adaptive immune response. Each antibody is specific to a particular antigen—this means it can bind to a unique molecular feature present on a pathogen, marking it for destruction.

Once bound, antibodies can neutralize the pathogen directly by blocking its ability to infect cells or by agglutinating multiple pathogens together, making them easier targets for other immune cells. Additionally, antibodies can activate the complement system, which enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells.

In summary, the central role of antibodies in identifying and neutralizing pathogens is vital for maintaining the body's defense mechanisms against infections and diseases.