When comparing an IgG molecule with a Fab fragment obtained from the same clonal population, the affinity for the antigen of interest would be ________, and the avidity of the two for the antigen of interest would be ________.

Question

Quizplus · Accepted Answer

Affinity refers to the strength of the binding of a single antibody-binding site and its corresponding antigenic determinant.Avidity refers to the overall binding of one antibody molecule to the corresponding antigen and includes the sum of binding sites for the whole antibody molecule.Thus the Fab fragment and the IgG molecule would have the same affinity for the antigen, but the IgG molecule would have a greater avidity because it has two binding sites, whereas the Fab fragment has only one binding site.

When Comparing an IgG Molecule with a Fab Fragment Obtained