The action of a drug molecule often depends on its shape. Discuss a specific example of a drug where one stereoisomer has a different physiological activity to the other.

one enantiomer/isomer of thalidomide relieves nausea/morning sickness;

other enantiomer/isomer of thalidomide causes foetal deformities;

OR

one enantiomer/isomer of taxol is an anti-cancer drug;

other enantiomer/isomer of taxol is ineffective;

OR

cis-isomer of diamminedichloroplatinum(II)/cisplatin is an anti-cancer drug;

trans-isomer is ineffective;

Whilst a drug in which stereochemistry was important was well known (usually Thalidomide), the other two parts of the question were poorly answered in very vague terms. Few seemed to realize the importance of the 3D modelling of the drug and its active site or to have grasped the concept that combinatorial chemistry involved the random ordering of specific chemical building blocks.