The antibody production persists for longer and reaches up to ten times the concentration of antibody produced in the initial antigenic challenge. Classic defense against a pathogen involves antibody binding to the pathogens antigens. This signals the immune cells that the substrate the antibodies are bound to should be destroyed. Immune cells will link to the antibodies via Fc receptors. This receptor linking activates the immune cell into destroying the pathogen.
Shape is what defines which antigen shape the antibody can bind.
Actual binding is an active process involving several chemical and electrical interactions between the antigen and antibody receptor. Electrical bonding works in two ways. Overall, antibodies are negatively charged whereas antigens are frequently positively charged. The electrostatic attraction between the two can help keep them together. Essentially each atom of a molecule has a net positive or negative charge depending on how many electrons it contains.