Pharmacy Pharmaceutical Chemistry 5

Question 1

Which functional group is present in ACE inhibitors like captopril that binds to the zinc ion at the active site of angiotensin-converting enzyme?

Accepted Answer

Thiol (-SH)

Answer

Captopril's thiol (-SH) group coordinates directly to the zinc ion in the ACE active site, providing potent enzyme inhibition.

Question 2

The process by which a drug salt dissolves and the parent drug is released is called:

Accepted Answer

Dissociation

Answer

Dissociation of a drug salt in aqueous solution separates the drug molecule (free acid or base) from its counterion, affecting solubility and absorption.

Question 3

Glucuronidation, a major Phase II metabolic reaction, involves the transfer of glucuronic acid from:

Accepted Answer

UDP-glucuronic acid (UDPGA) to the drug

Answer

UDP-glucuronosyltransferase (UGT) enzymes transfer glucuronic acid from UDPGA to hydroxyl, carboxyl, amino, or thiol groups on drug molecules.

Question 4

Which type of drug-receptor interaction is strongest and irreversible under physiological conditions?

Accepted Answer

Covalent bonding

Answer

Covalent bonds are the strongest drug-receptor interactions, generally irreversible, as seen with aspirin's acetylation of COX or organophosphate inhibition of acetylcholinesterase.

Question 5

The polymorphic forms of a drug substance are important in pharmacy because they can differ in:

Accepted Answer

Solubility, stability, and bioavailability

Answer

Polymorphs have the same chemical composition but different crystal packing, affecting dissolution rate, solubility, stability, and ultimately bioavailability.

Pharmacy Practice Test

Pharmacy Practice Test

Pharmacy Pharmaceutical Chemistry 5