A penicillin reaction is a life-threatening event. In those who are allergic to penicillin, the drug acts as a that binds to blood proteins, causing a strong immune response.

A penicillin reaction is a life-threatening event. In those who are allergic to penicillin, the drug acts as a hapten that binds to blood proteins, causing a strong immune response.

Explanation:

Low molecular weight chemicals can bind to antibodies, but cannot activate B lymphocytes by themselves (they are not immunogenic). To generate specific antibodies to these small chemicals, immunologists typically bind them to macromolecules prior to immunization. In these cases, the chemical is called a hapten. Penicillin G is a typical hapten that tends to covalently bind to lysine residues both in solution and in protein-bound cells. Penicillin is a drug that behaves as a hapten, since the beta-lactam ring under physiological conditions opens and reacts with the lysine residues of proteins, forming a complex that is the main antigenic determinant of penicillin and other beta-lactams and is capable of to stimulate responses mediated by antibodies or by T cells.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

i believe the answer would be b. hope it : )