Sources of enzymes MCQs With Answer

Introduction

This quiz set on Sources of Enzymes is tailored for M.Pharm students studying Advanced Pharmaceutical Biotechnology. It covers microbial, plant, animal and recombinant origins of enzymes, emphasizing industrial and pharmaceutical relevance. Questions focus on practical aspects such as extracellular vs intracellular production, strain selection, fermentation strategies, extremophiles as enzyme sources, and modern discovery methods like metagenomics and heterologous expression. Each item aims to reinforce conceptual understanding and application—selecting appropriate enzyme sources, anticipating downstream processing challenges, and appreciating biochemical/biotechnological constraints. Use these MCQs to test knowledge, prepare for exams, and deepen insight into enzyme sourcing for drug development and bioprocessing.

Q1. Which microbial source is most commonly used for industrial production of thermostable DNA polymerases used in PCR?

• Escherichia coli
• Thermus aquaticus
• Bacillus subtilis
• Aspergillus niger

Correct Answer: Thermus aquaticus

Q2. Which of the following enzymes is classically obtained from plant sources and widely used as a proteolytic agent in pharmaceutical formulations?

• Trypsin
• Pepsin
• Papain
• Lipase

Correct Answer: Papain

Q3. Which production strategy is preferred when the enzyme is secreted extracellularly in large quantities by the microorganism?

• Cell disruption and intracellular extraction
• Direct recovery from culture supernatant
• Plant tissue maceration
• Animal organ homogenization

Correct Answer: Direct recovery from culture supernatant

Q4. Which yeast species is commonly used for heterologous expression of secreted pharmaceutical enzymes with eukaryotic post-translational modifications?

• Bacillus subtilis
• Pichia pastoris
• Escherichia coli
• Thermus thermophilus

Correct Answer: Pichia pastoris

Q5. Which of the following is a major advantage of using microbial enzymes over animal-derived enzymes in pharmaceutical manufacturing?

• Lower thermal stability
• Greater batch-to-batch variability
• Ethical and supply-chain benefits with scalable fermentation
• Requirement for complex animal tissues

Correct Answer: Ethical and supply-chain benefits with scalable fermentation

Q6. Extremophiles are valuable enzyme sources because their enzymes often exhibit which characteristic beneficial for industrial processes?

• High sensitivity to organic solvents
• Unusual substrate specificity that limits use
• Enhanced stability under extreme temperature or pH
• Inability to be expressed heterologously

Correct Answer: Enhanced stability under extreme temperature or pH

Q7. Which bacterial genus is a common source of commercial amylases used in starch processing and detergent formulations?

• Clostridium
• Bacillus
• Lactobacillus
• Streptococcus

Correct Answer: Bacillus

Q8. Metagenomic approaches help discover novel enzymes from environmental samples primarily by:

• Directly culturing all microorganisms from a sample
• Sequencing and functionally screening DNA extracted from uncultured microbes
• Extracting enzymes only from laboratory strains
• Using animal tissue extracts to mimic environmental enzymes

Correct Answer: Sequencing and functionally screening DNA extracted from uncultured microbes

Q9. Which plant-derived enzyme is widely used as an anti-inflammatory and digestive aid and is commercially extracted from pineapple?

• Bromelain
• Cellulase
• Rennin
• Invertase

Correct Answer: Bromelain

Q10. Why is Escherichia coli a preferred host for recombinant enzyme production despite lacking eukaryotic glycosylation?

• It provides eukaryotic post-translational modifications by default
• It has fast growth, high yield, well-understood genetics and low cost
• It is the only host able to secrete large glycoproteins
• It inherently produces thermostable enzymes

Correct Answer: It has fast growth, high yield, well-understood genetics and low cost

Q11. Which source is most likely chosen when an enzyme requires human-like glycosylation for therapeutic application?

• Escherichia coli expression
• Filamentous fungi like Aspergillus niger
• Mammalian cell culture systems
• Plant leaf extracts

Correct Answer: Mammalian cell culture systems

Q12. Which enzyme is typically derived from animal pancreas and used as a digestive aid in pharmaceutical formulations?

• Pectinase
• Pancreatin
• Cellulase
• Invertase

Correct Answer: Pancreatin

Q13. What is a common challenge when sourcing enzymes from filamentous fungi for pharmaceutical use?

• Excessive secretion into medium simplifying purification
• Risk of mycotoxin co-production and complex downstream purification
• Inability to grow in bioreactors
• Universal absence of post‑translational modifications

Correct Answer: Risk of mycotoxin co-production and complex downstream purification

Q14. Immobilized whole-cell biocatalysts are chosen over free enzymes primarily because they:

• Cannot be reused and have higher cost
• Improve enzyme stability and allow repeated use of the biocatalyst
• Require continuous cell lysis
• Always produce purer end products without downstream steps

Correct Answer: Improve enzyme stability and allow repeated use of the biocatalyst

Q15. Which characteristic is most important when selecting a microbial strain for large-scale extracellular enzyme production?

• High intracellular enzyme accumulation
• Natural ability to secrete the enzyme and high specific productivity
• Production restricted to complex multicellular growth forms
• Extremely slow growth to facilitate control

Correct Answer: Natural ability to secrete the enzyme and high specific productivity

Q16. Which marine source is increasingly explored for enzymes with unique cold‑adapted activities useful in low-temperature pharmaceutical processes?

• Desert soil bacteria
• Thermophilic hot spring microbes
• Psychrophilic marine microorganisms
• Terrestrial fungi only

Correct Answer: Psychrophilic marine microorganisms

Q17. Which factor most directly affects the glycosylation pattern of a recombinant enzyme expressed in a host organism?

• The pH of the storage buffer only
• Host cell type and its glycosylation machinery
• The color of the fermentation broth
• The molecular weight marker used in SDS-PAGE

Correct Answer: Host cell type and its glycosylation machinery

Q18. In commercial enzyme production from microbes, why is extracellular secretion often preferred over intracellular expression?

• Extracellular enzymes always have higher specific activity
• Secretion simplifies recovery and reduces cost of cell disruption
• Intracellular enzymes cannot be stabilized
• Extracellular secretion guarantees absence of contaminants

Correct Answer: Secretion simplifies recovery and reduces cost of cell disruption

Q19. Which technique is most useful to identify novel enzyme activities from environmental DNA without culturing organisms?

• Classical plate streaking and isolation
• Metagenomic functional screening
• Animal tissue digestion assays
• Standard fermentation of known lab strains

Correct Answer: Metagenomic functional screening

Q20. Which of the following enzyme examples correctly matches its common commercial biological source?

• Amylase — Mammalian liver
• Pectinase — Bacillus subtilis
• Protease (fungal) — Aspergillus species
• Lipase — Thermus aquaticus

Correct Answer: Protease (fungal) — Aspergillus species

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