Question

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.)

Answer 1

a. Non-Competitive

b. Competitive

c. The substrate is acetylcholine. The products are acetic acid and choline.

Step-by-step explanation:

a. Non-Competitive. Here, the inhibitor binds to the enzymes allosteric site. This action changes the shape of the enzymes active site, so that it can no longer bind to the correct substrate.

b. Competitive. Here, the inhibitor binds directly to the enzymes active site, thereby blocking other substrates.

c. A "substrate" is the molecule that binds to an enzyme. The "product" is what the enzyme produces after it acts upon the substrate.