Applications of immobilized enzymes in pharmaceutical industries explore how enzyme immobilization and biocatalysis revolutionize drug synthesis, offering enhanced enzyme stability, reusability, and process optimization. Immobilized enzymes—attached to carriers like agarose, silica, polymers or nanoparticles via adsorption, covalent binding, entrapment or cross‑linking—enable stereoselective synthesis of chiral intermediates, antibiotic modification, and continuous manufacturing in packed‑bed reactors. Key benefits include improved thermal and operational stability, simplified downstream processing, and cost‑effective scale‑up, while challenges involve mass transfer limitations, enzyme leaching, and regulatory controls. Understanding immobilization methods, kinetics (Km/Vmax changes), supports, and reactor design is essential for B.Pharm students. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary practical advantage of using immobilized enzymes in pharmaceutical production?
- Increased enzyme genetic stability
- Higher reusability of the catalyst
- Faster enzyme evolution
- Reduced need for buffers
Correct Answer: Higher reusability of the catalyst
Q2. Which immobilization method typically forms a covalent bond between enzyme and support?
- Adsorption
- Entrapment
- Covalent binding
- Physical encapsulation
Correct Answer: Covalent binding
Q3. Which support material is commonly used in pharmaceutical immobilized enzyme preparations for its low nonspecific binding and high biocompatibility?
- Agarose beads
- Glass wool
- Cellulose paper
- Raw activated carbon
Correct Answer: Agarose beads
Q4. How does immobilization commonly affect the apparent Michaelis constant (Km) of an enzyme?
- Apparent Km always decreases
- Apparent Km remains unchanged
- Apparent Km may increase due to diffusion limitations
- Km is replaced by a different constant
Correct Answer: Apparent Km may increase due to diffusion limitations
Q5. Cross‑linked enzyme aggregates (CLEAs) are prepared by which core process?
- Physical adsorption onto hydrophobic beads
- Cross‑linking precipitated enzyme molecules
- Entrapment within alginate beads only
- Immobilization via ionic exchange resins
Correct Answer: Cross‑linking precipitated enzyme molecules
Q6. Which enzyme is widely used immobilized for penicillin G to 6‑APA conversion in antibiotic production?
- Lipase
- Penicillin acylase
- Glucose oxidase
- Alcohol dehydrogenase
Correct Answer: Penicillin acylase
Q7. Which type of reactor is most commonly used for continuous processes with immobilized enzymes in industry?
- Batch stirred tank
- Packed‑bed reactor
- Bench-top shake flask
- Membrane dialysis unit
Correct Answer: Packed‑bed reactor
Q8. What is the main drawback frequently encountered with immobilized enzyme systems?
- Unlimited thermal stability
- Mass transfer and diffusion limitations
- Uncontrollable genetic changes
- Instant self‑regeneration
Correct Answer: Mass transfer and diffusion limitations
Q9. Immobilization typically has what effect on enzyme thermal stability?
- Decreases thermal stability
- Has no effect on thermal stability
- Often increases thermal stability
- Causes irreversible denaturation
Correct Answer: Often increases thermal stability
Q10. Which parameter is most relevant to assess practical performance of an immobilized enzyme in production?
- Operational stability (activity retained over repeated cycles)
- DNA sequence fidelity
- Color of the support material
- Volume of buffer used
Correct Answer: Operational stability (activity retained over repeated cycles)
Q11. Which immobilization strategy best minimizes enzyme leaching during continuous use?
- Physical adsorption
- Entrapment without cross‑linking
- Covalent binding to the support
- Simple mixing in solution
Correct Answer: Covalent binding to the support
Q12. Co‑immobilization of multiple enzymes on one support is primarily used to:
- Enhance enzyme genetic diversity
- Enable multistep cascade reactions in one reactor
- Reduce carrier surface area
- Increase substrate toxicity
Correct Answer: Enable multistep cascade reactions in one reactor
Q13. Immobilization tends to affect the apparent Vmax of an enzyme by:
- Always increasing apparent Vmax
- Often reducing apparent Vmax due to restricted mobility and diffusion
- Eliminating the need for Vmax measurement
- Converting Vmax into Km
Correct Answer: Often reducing apparent Vmax due to restricted mobility and diffusion
Q14. Why are nanoparticles attractive supports for enzyme immobilization in pharmaceutical applications?
- They have low surface area
- They offer high surface area and tunable surface chemistry
- They prohibit substrate access
- They are always magnetic regardless of composition
Correct Answer: They offer high surface area and tunable surface chemistry
Q15. Which class of enzymes is extensively used immobilized for stereoselective esterification and resolution of chiral drugs?
- Proteases
- Kinases
- Lipases
- Polymerases
Correct Answer: Lipases
Q16. Which immobilization method is generally reversible and allows easy enzyme desorption?
- Covalent binding
- Adsorption
- Cross‑linking
- Entrapment in resin
Correct Answer: Adsorption
Q17. Entrapment as an immobilization technique refers to:
- Forming covalent bonds between enzyme and support surface
- Physically trapping enzyme inside a porous gel matrix
- Drying enzymes onto paper
- Biotinylating enzymes for affinity capture
Correct Answer: Physically trapping enzyme inside a porous gel matrix
Q18. Which dimensionless number is often used to assess internal diffusion limitations in porous immobilized enzyme particles?
- Reynolds number
- Thiele modulus
- Péclet number
- Schmidt number
Correct Answer: Thiele modulus
Q19. What sterilization challenge specifically affects immobilized enzyme preparations?
- Autoclaving can denature both enzyme and support
- Sterilization always enhances activity
- Gamma irradiation creates more active sites
- Filtration sterilization cross‑links enzymes
Correct Answer: Autoclaving can denature both enzyme and support
Q20. Which immobilized enzyme is classically used industrially for glucose to fructose isomerization (relevant to biocatalysis knowledge)?
- Penicillin acylase
- Glucose isomerase
- Alcohol oxidase
- Transaminase
Correct Answer: Glucose isomerase
Q21. Which analytical techniques are commonly used to characterize immobilized enzyme morphology and chemical bonding?
- NMR only
- FTIR and SEM analysis
- Mass spectrometry of intact reactor
- Colorimetry of support
Correct Answer: FTIR and SEM analysis
Q22. Which cross‑linking reagent is widely used to link enzymes to supports or to cross‑link enzyme aggregates?
- Sodium chloride
- Glutaraldehyde
- Ethanol
- Acetic acid
Correct Answer: Glutaraldehyde
Q23. How does enzyme immobilization typically benefit downstream processing in pharmaceutical manufacture?
- Complicates product separation
- Makes enzyme‑product separation easier and reduces contamination
- Requires more solvent extraction steps
- Eliminates need for purification
Correct Answer: Makes enzyme‑product separation easier and reduces contamination
Q24. Compared to free enzymes, immobilized enzymes usually exhibit which shelf‑life characteristic?
- Shorter shelf‑life under all conditions
- Longer shelf‑life due to stabilized conformation
- Immediate inactivation at room temperature
- No measurable shelf‑life
Correct Answer: Longer shelf‑life due to stabilized conformation
Q25. For preserving delicate native enzyme conformation while still enabling reuse, which immobilization strategy is often preferred?
- Covalent cross‑linking with harsh agents
- Entrapment in hydrogel beads
- Dry heat binding to silica
- Strong ionic adsorption at extreme pH
Correct Answer: Entrapment in hydrogel beads
Q26. How can immobilization complicate interpretation of enzyme inhibition studies?
- It eliminates all inhibitory effects
- It may cause apparent changes in inhibition constants due to diffusion effects
- It makes inhibitors permanently bind to the support
- It converts competitive inhibitors into activators
Correct Answer: It may cause apparent changes in inhibition constants due to diffusion effects
Q27. A major regulatory concern for immobilized enzyme use in pharmaceutical processes is:
- Enzyme leaching and carrier residue contamination in the product
- Too high genetic variability of the enzyme
- Excessive fluorescence of supports
- Color matching of batches
Correct Answer: Enzyme leaching and carrier residue contamination in the product
Q28. An ideal property of a porous carrier for immobilized enzymes is:
- Very small pore size smaller than enzyme molecules
- High porosity with pore size permitting substrate diffusion
- Complete impermeability to liquids
- Reactive surface that degrades enzyme
Correct Answer: High porosity with pore size permitting substrate diffusion
Q29. In pharmaceutical synthesis, immobilized enzymes are particularly valuable for:
- Random polymerization of drug molecules
- Biocatalytic synthesis of chiral drug intermediates with high enantioselectivity
- Uncontrolled oxidation of APIs
- Replacing all chemical catalysts without optimization
Correct Answer: Biocatalytic synthesis of chiral drug intermediates with high enantioselectivity
Q30. Which term best describes the ability to run an immobilized enzyme multiple successive production batches?
- Inhibitory potential
- Reusability
- Genetic drift
- Solubility index
Correct Answer: Reusability
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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