B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) 2 — Questions and Answers
Question 1: Which enzyme is responsible for the conversion of arachidonic acid to prostaglandins?
- Lipoxygenase
- Cyclooxygenase (COX) (Correct answer)
- Phospholipase A2
- Thromboxane synthase
Correct answer: Cyclooxygenase (COX)
Cyclooxygenase (COX) catalyzes the conversion of arachidonic acid to prostaglandin H2, the precursor to prostaglandins and thromboxanes.
Question 2: The Henderson-Hasselbalch equation is used in pharmacy primarily to:
- Calculate drug half-life
- Predict the ionization state of a drug at a given pH (Correct answer)
- Determine protein binding affinity
- Calculate volume of distribution
Correct answer: Predict the ionization state of a drug at a given pH
The Henderson-Hasselbalch equation relates pH, pKa, and the ratio of ionized to unionized drug forms, predicting drug absorption and distribution.
Question 3: Which of the following is an example of a prodrug that requires hepatic activation?
- Aspirin
- Codeine (Correct answer)
- Morphine
- Ibuprofen
Correct answer: Codeine
Codeine is a prodrug converted by CYP2D6 in the liver to morphine, which is the pharmacologically active metabolite responsible for analgesia.
Question 4: What is the primary mechanism of resistance to beta-lactam antibiotics in bacteria?
- Efflux pumps
- Altered penicillin-binding proteins
- Beta-lactamase enzyme production (Correct answer)
- Decreased outer membrane permeability
Correct answer: Beta-lactamase enzyme production
Beta-lactamase enzymes produced by resistant bacteria hydrolyze the beta-lactam ring, rendering the antibiotic inactive.
Question 5: In pharmacokinetics, zero-order kinetics means that drug elimination occurs:
- At a rate proportional to drug concentration
- At a constant rate regardless of drug concentration (Correct answer)
- Exponentially with time
- Only via renal clearance
Correct answer: At a constant rate regardless of drug concentration
Zero-order kinetics describes elimination at a fixed amount per unit time, independent of drug concentration, as seen with alcohol and phenytoin at high doses.
Question 6: Which layer of the skin provides the greatest barrier to topical drug absorption?
- Stratum granulosum
- Stratum spinosum
- Stratum corneum (Correct answer)
- Dermis
Correct answer: Stratum corneum
The stratum corneum, composed of dead, keratin-filled cells, is the primary rate-limiting barrier to percutaneous drug absorption.
Question 7: Which buffer system is most important for maintaining blood pH homeostasis in humans?
- Phosphate buffer system
- Bicarbonate-carbonic acid system (Correct answer)
- Protein buffer system
- Ammonia buffer system
Correct answer: Bicarbonate-carbonic acid system
The bicarbonate-carbonic acid buffer system is the most physiologically important blood buffer because it is regulated by both the lungs and kidneys.
B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) 2
Which enzyme is responsible for the conversion of arachidonic acid to prostaglandins?