Question

7. A small molecule that can react with preformed antibodies but can not, by itself, induce their for-mation is referred to as a (an) (A) complete antigen (B) antigenic determinant (C) hapten (D) helper factor (E) suppressor factor

Answer 1

A small molecule that can react with preformed antibodies but can not, by itself, induce their formation is referred to as a

(C) Hapten

Haptens are not immunogens by themselves. They require linkage to a larger host protein or foreign protein to become immunogenic. Haptens are self conjugating antigen moeties that can modify epitopes and provide new binding specifications. Haptens can be recognized by T cells on binding covalently or non covalently complexed with peptides while haptens can modify epitopes of antigen recognized by antibodies.

Haptens can be chemical made synthetically in the laboratory or natural when introduced into host. Examples include Trinitrophenol(picric acid), pencillin, urushiol which is a toxin found in poison ivy .