What are antibodies and how do they work?

Antibodies are proteins which belong to a class known as immunoglobulins. They are made up of chains of amino acids joined by peptide bonds. Antibodies have an important role in the immune system of many animals. They have several functions, for example: coating the pathogen so the phagocyte can detect and engulf it more easily, coating the pathogen to prevent it from entering host cells, or binding to and neutralising toxins produced by the pathogen.

Plasma cells are are type of immune cell that produce antibodies. Plasma cells are B-cells, a type of white blood cell. When a pathogen is recognised by a B-cell, the B-cell is activated and divides into many plasma cells which in turn produce many antibodies specific to the antibody encountered.