a molecule or portion of a molecule capable of binding to the combining site of an antibody. For every given antigenic determinant, the body can construct a variety of antibody-combining sites some of, the small site of an "antigen" to which the "antibody" can attach itself by its combining site. Several antigenic determinants may be carried by a single antigenic molecule., (struktuuriliselt tuntud) antigeense toimega molekuliosa