The specific action of an enzyme with a single substrate can be explained using a Lock and Key analogy first postulated in 1894 by Emil Fischer. In this analogy, the lock is the enzyme and the key is the substrate. Only the correctly sized key (substrate) fits into the key hole (active site) of the lock (enzyme).
I believe its because the blood from Mouse A had anthrax in the blood stream so it is still in the blood when yu put it into Mouse B so then Mouse B develops the same thing Mouse A had.
