1. Geometrical isomerism, such as cis-trans isomerism, can create different pharmacological effects because the orientation of atoms determines if a drug can properly bind to its target, like how only the cis isomer of cisplatin can bind to DNA in cancer cells. 2. Chirality is important in drug action because two enantiomers of a drug act differently in the body, with one potentially causing harmful side effects like thalidomide while the other has the desired effect. 3. The beta-lactam ring in penicillin is important because its strained structure makes it highly reactive and able to covalently bond to bacterial cell wall enzymes, blocking their action.