The function. They are both proteins. But enzymes are defined by being able to catalyze a reaction. read more
Another difference between antigen and antibody is where they are. Antigens are “hooks” on the surface of cells and are found in nearly every cell. You can find IgA antibodies in the vagina, eyes, ears, digestive tract, breathing passages, and nose, as well as in blood, tears, and saliva. read more