Classification of Penicillin. 1  Natural Penicillins (Penicillin V, Penicillin G, Benzathine, Procaine Penicillin) 2  Penicillinase-Resistant Penicillins (Oxacillin, Dicloxacillin, Cloxacillin, Methicillin, Nafcillin) 3  Aminopenicillins (Amoxicillin, Bacampicillin, Ampicillin) 4  Extended Spectrum Penicillins.
the system is usually defined as the chemical reaction and the boundary is the container in which the reaction is run in the course of the reaction heat is either given off or absorbed by the system furthermore the system either does work on it surroundings or has work done on it by its surroundings
In chemistry, a substrate is typically the chemical species being observed in a chemical reaction, which is organic in nature and reacts with a reagent to generate a product. In synthetic and organic chemistry, the substrate is the chemical of interest that is being modified.