Pharmaceutical Chemistry Flashcards

Which functional group is responsible for the acidic character of aspirin (acetylsalicylic acid)?

Answer: Carboxylic acid group

The carboxylic acid (-COOH) group in aspirin donates a proton, giving it its acidic character with a pKa of ~3.5.

The Henderson-Hasselbalch equation is primarily used in pharmacy to:

Answer: Calculate the ratio of ionized to unionized drug forms at a given pH

Henderson-Hasselbalch (pH = pKa + log[A⁻]/[HA]) calculates the ionization ratio of weak acids/bases at physiological pH, which affects absorption.

Which stereochemical descriptor system is used to unambiguously name chiral centers in drug molecules?

Answer: R/S (Cahn-Ingold-Prelog) system

The R/S (Cahn-Ingold-Prelog) system assigns priority to substituents by atomic number and unambiguously designates absolute configuration at chiral centers.

Prodrugs are compounds that:

Answer: Require biotransformation in the body to become active

Prodrugs are pharmacologically inactive precursors converted in vivo (typically by enzymes) to the active drug form to improve bioavailability or reduce toxicity.

What is the primary mechanism by which beta-lactam antibiotics exert their antibacterial effect?

Answer: Inhibiting bacterial cell wall transpeptidase (PBPs)

Beta-lactam antibiotics irreversibly acylate and inhibit penicillin-binding proteins (transpeptidases), blocking cross-linking of peptidoglycan in bacterial cell walls.

Optical rotation is measured using a:

Answer: Polarimeter

A polarimeter measures the angle of rotation of plane-polarized light by a chiral compound, expressed as specific rotation [α].

Which type of isomerism involves compounds with the same molecular formula but different spatial arrangements that are non-superimposable mirror images?

Answer: Enantiomerism

Enantiomers are non-superimposable mirror images of each other, differing only in the configuration at one or more chiral centers.