An understanding of basic organic chemical reactivity is key for many biosciences students. The reactivities of different carbonyl groups affect their function in many biomolecules. A practical class, the two-step synthesis of paracetamol, has been devised to illustrate the electrophilic reactivities of carbonyls, which was covered in the accompanying lecture program. Students also examine the UV, IR, NMR, and mass spectra of the esters and amides, building further on the understanding gained in lectures. The practical work itself has been devised to be able to be run in bioscience laboratories with limited chemical facilities. The class has been enhanced during four academic years with strong support from the students.