4. Many beneficial drugs work by inhibiting enzymes. Penicillin blocks an enzyme that bacteria use in making cell walls. Ibuprofen inhibits an enzyme involved in sending pain signals. Many cancer drugs inhibit enzymes that promote cell division. (3.5 pt.) a. Recall the two mechanisms of enzyme inhibition. Which of these alters the shape of the enzyme? (1 pt.) b. Nerve gases (a form of chemical warfare) irreversibly bind to the active site of an enzyme called acetylcholinesterase vital to transmitting nerve impulses, leading to rapid paralysis and death. What mechanism of enzyme inhibition is exemplified? (1 pt.) c. The enzyme acetylcholinesterase normally binds the neurotransmitter acetylcholine and breaks it down to acetic acid and choline. What is the enzyme’s substrate(s)? What is the enzyme’s product(s)? (1.5 pt.)