What is the primary function of an antibody?

The primary function of an antibody is to act against a specific antigen. Antibodies are proteins produced by the immune system in response to antigens, which are foreign substances such as bacteria, viruses, and toxins. Each antibody is designed to bind specifically to its corresponding antigen, marking it for destruction by other components of the immune system. This binding action helps neutralize pathogens and facilitate their removal from the body, playing a crucial role in immune defense.

The other options describe substances that do not align with the fundamental role of antibodies. Carbohydrates primarily serve as energy sources and structural components in cells, but they do not function specifically as protective agents against pathogens. Lipids are more associated with energy storage and cellular membrane structure than with immune response. Enzymes, while essential for catalyzing biochemical reactions, do not serve the immune function characteristic of antibodies. Therefore, the correct understanding of an antibody's role is centered on its specific action against antigens, highlighting its importance in the immune response.