Penicilllin
Penicillin is an antibiotic that is used to treat bacterial infections. Penicillin kills susceptible bacteria by specifically inhibiting the transpeptidase that catalyzes the final step in cell wall biosynthesis, the cross-linking of peptidoglycan[1]. Penicilllin inhibits this by bidnding to bacterial proteins, penicillin binding proteins. Penicillin is able to bind to these because their chemical structure is similar to that of the sugar–amino acid backbone that forms peptidoglycan. Penicillin was first identified by Alexander Fleming when he accidentally left the lid of one of his petri dishes open and returned to find the Penicillin notatum fungi developing on the dish generating Penicillin[2].