Recombinant proteins are a cornerstone of the biopharmaceutical industry, representing some of the most innovative and effective treatments available today. From therapeutic hormones like insulin and erythropoietin to highly specific monoclonal antibodies, these drugs have transformed patient care. For PharmD students, a solid understanding of how these complex molecules are designed, produced, purified, and formulated is essential for managing patients on these advanced therapies and appreciating the nuances that differentiate them from small-molecule drugs.
1. A recombinant protein is best defined as a protein that is:
- Extracted directly from a human source
- Produced in a host organism that has received a gene from another organism
- Synthesized chemically from individual amino acids
- Found naturally only in bacteria
Answer: Produced in a host organism that has received a gene from another organism
2. What is a primary disadvantage of using prokaryotic systems like E. coli for producing complex human therapeutic proteins?
- They have very slow growth rates.
- The genetic code is different from humans.
- Lack of machinery for post-translational modifications like glycosylation.
- They are extremely expensive to culture.
Answer: Lack of machinery for post-translational modifications like glycosylation.
3. The first human therapeutic protein produced using recombinant DNA technology and approved for use was:
- Erythropoietin
- Human growth hormone
- Insulin
- Factor VIII
Answer: Insulin
4. In the context of producing a recombinant protein, what is the function of a plasmid?
- It acts as the protein product itself
- It serves as a vector to introduce the gene of interest into a host cell
- It is an enzyme that purifies the final protein
- It provides the nutrients for cell growth
Answer: It serves as a vector to introduce the gene of interest into a host cell
5. Which of the following host systems is most suitable for producing a recombinant protein that requires complex glycosylation to be active?
- Escherichia coli
- Bacillus subtilis
- Chinese Hamster Ovary (CHO) cells
- Bacteriophage T4
Answer: Chinese Hamster Ovary (CHO) cells
6. The process of inducing a host cell, such as E. coli, to take up foreign DNA is called:
- Transcription
- Translation
- Transformation
- Transduction
Answer: Transformation
7. “Downstream processing” in the manufacturing of recombinant proteins refers to:
- The initial cloning of the gene
- The fermentation or cell culture phase
- The purification and formulation of the protein after expression
- The design of the clinical trials
Answer: The purification and formulation of the protein after expression
8. Affinity chromatography is a powerful purification technique that separates proteins based on:
- Their specific binding to a ligand or antibody
- Their overall size and shape
- Their net electrical charge
- Their solubility in different solvents
Answer: Their specific binding to a ligand or antibody
9. What is a major concern regarding the immunogenicity of recombinant proteins?
- The protein will not be effective
- The patient may develop an immune response, creating antibodies against the therapeutic protein
- The protein will be too stable in the bloodstream
- The manufacturing process will be too simple
Answer: The patient may develop an immune response, creating antibodies against the therapeutic protein
10. Erythropoietin (EPO) is a recombinant protein used to treat anemia. What is its primary function?
- It stimulates the production of white blood cells
- It stimulates the production of red blood cells
- It helps with blood clotting
- It lowers cholesterol levels
Answer: It stimulates the production of red blood cells
11. The term “gene pharming” describes the use of what to produce recombinant proteins?
- Large industrial chemical plants
- Transgenic animals or plants
- Deep-sea bacteria
- Computer simulations
Answer: Transgenic animals or plants
12. Lyophilization (freeze-drying) is a technique used during the formulation of some protein drugs to:
- Increase the protein’s solubility in water
- Add glycosylation patterns
- Improve the long-term stability of the protein
- Ensure the protein is denatured
Answer: Improve the long-term stability of the protein
13. A “fusion protein” is a type of recombinant protein where:
- Two different proteins are chemically bonded after purification
- A protein is fused to a radioactive isotope
- Two or more genes are joined together to create a single polypeptide with combined functions
- The protein is designed to be insoluble
Answer: Two or more genes are joined together to create a single polypeptide with combined functions
14. What is the role of post-translational modifications (PTMs) for many therapeutic proteins?
- They are always undesirable and must be removed
- They are critical for proper folding, stability, and biological activity
- They only occur in bacterial expression systems
- They have no impact on the protein’s function
Answer: They are critical for proper folding, stability, and biological activity
15. Monoclonal antibodies are a major class of recombinant protein therapies. Their high specificity is due to their ability to:
- Bind to many different targets simultaneously
- Bind to a single, specific epitope on an antigen
- Easily cross the blood-brain barrier
- Self-replicate within the patient’s body
Answer: Bind to a single, specific epitope on an antigen
16. What is the primary purpose of adding a “tag” (like a His-tag) to a recombinant protein?
- To make the protein radioactive
- To aid in its purification via affinity chromatography
- To increase its immunogenicity
- To make it insoluble
Answer: To aid in its purification via affinity chromatography
17. If a recombinant protein is produced intracellularly in E. coli, it often forms insoluble aggregates known as:
- Plasmids
- Inclusion bodies
- Exosomes
- Ribosomes
Answer: Inclusion bodies
18. SDS-PAGE is a laboratory technique used to:
- Determine the purity and approximate molecular weight of a protein
- Sequence the gene that codes for a protein
- Amplify the amount of a protein
- Test the biological activity of a protein
Answer: Determine the purity and approximate molecular weight of a protein
19. A key challenge in the oral delivery of therapeutic proteins is that they are:
- Too small to be absorbed
- Generally stable in the acidic environment of the stomach
- Prone to degradation by proteases in the GI tract and are poorly absorbed
- Ineffective when administered by any route other than orally
Answer: Prone to degradation by proteases in the GI tract and are poorly absorbed
20. The suffix “-cept” in a drug name (e.g., etanercept) typically indicates the drug is a:
- Monoclonal antibody
- Receptor fusion protein
- Synthetic peptide
- Small molecule kinase inhibitor
Answer: Receptor fusion protein
21. In the process of creating a recombinant protein, what is the role of reverse transcriptase?
- To synthesize DNA from a protein template
- To synthesize mRNA from a DNA template
- To synthesize complementary DNA (cDNA) from an mRNA template
- To join DNA fragments together
Answer: To synthesize complementary DNA (cDNA) from an mRNA template
22. Which of the following is a critical parameter to control in a bioreactor during cell culture?
- pH, temperature, and dissolved oxygen levels
- The color of the growth medium
- The time of day
- The brand of the glassware used
Answer: pH, temperature, and dissolved oxygen levels
23. Why can even a single amino acid change potentially render a recombinant protein therapeutically useless?
- It can drastically alter the protein’s 3D structure and function
- It will always make the protein more stable
- It has no effect on protein structure
- It makes the purification process easier
Answer: It can drastically alter the protein’s 3D structure and function
24. The term “humanized” when referring to a monoclonal antibody means that:
- It was produced in a human host cell
- The constant regions of a mouse antibody have been replaced with human sequences
- It is a completely synthetic antibody
- It is a polyclonal antibody from a human donor
Answer: The constant regions of a mouse antibody have been replaced with human sequences
25. A biosimilar drug must demonstrate that it has:
- An identical chemical structure to a small molecule drug
- No clinically meaningful differences in terms of safety, purity, and potency from an existing reference biologic
- Superior efficacy compared to the reference product
- A completely different mechanism of action than the reference product
Answer: No clinically meaningful differences in terms of safety, purity, and potency from an existing reference biologic
26. Which process is part of “upstream” bioprocessing?
- Final product formulation and filling
- Cell culture and expansion in a fermenter
- Chromatographic purification
- Lyophilization
Answer: Cell culture and expansion in a fermenter
27. Granulocyte colony-stimulating factor (G-CSF) is a recombinant protein that:
- Stimulates the production of neutrophils, a type of white blood cell
- Stimulates the production of red blood cells
- Lowers blood glucose
- Dissolves blood clots
Answer: Stimulates the production of neutrophils, a type of white blood cell
28. A key quality control step for parenteral protein drugs is testing for:
- The correct flavor profile
- Endotoxins, which can cause fever and shock
- The presence of DNA contamination only
- The correct color
Answer: Endotoxins, which can cause fever and shock
29. The main advantage of PEGylation (attaching polyethylene glycol) for a therapeutic protein is to:
- Increase its immunogenicity
- Decrease its solubility
- Increase its circulating half-life and reduce dosing frequency
- Make it easier to purify
Answer: Increase its circulating half-life and reduce dosing frequency
30. Tissue plasminogen activator (tPA) is a recombinant enzyme used therapeutically to:
- Form blood clots
- Lower blood pressure
- Dissolve blood clots in conditions like stroke and heart attack
- Stimulate red blood cell production
Answer: Dissolve blood clots in conditions like stroke and heart attack
31. The choice of expression system for a recombinant protein is LEAST dependent on:
- The required post-translational modifications
- The cost of production
- The desired yield of the protein
- The country where the research is being conducted
Answer: The country where the research is being conducted
32. What is the purpose of an expression vector that is different from a simple cloning vector?
- It only allows for the replication of the inserted gene.
- It contains regulatory sequences (like a promoter) necessary for the host cell to transcribe and translate the gene.
- It is made of RNA instead of DNA.
- It cannot be taken up by host cells.
Answer: It contains regulatory sequences (like a promoter) necessary for the host cell to transcribe and translate the gene.
33. An ELISA assay is often used during protein development to:
- Determine the exact 3D structure of the protein
- Quantify the amount of protein present in a sample
- Sequence the protein’s amino acids
- Measure the protein’s molecular weight
Answer: Quantify the amount of protein present in a sample
34. The cold chain is critical for the storage and transport of many recombinant protein drugs because:
- They are highly resistant to heat
- Freezing them improves their activity
- They are sensitive to temperature and can denature or aggregate if not kept cool
- They are flammable at room temperature
Answer: They are sensitive to temperature and can denature or aggregate if not kept cool
35. A major reason for developing second-generation recombinant proteins is to:
- Improve properties such as half-life, efficacy, or reduce immunogenicity
- Make the production process more difficult
- Ensure the new protein is identical to the first generation
- Increase the number of required daily injections
Answer: Improve properties such as half-life, efficacy, or reduce immunogenicity
36. A codon optimization strategy might be used when expressing a human gene in E. coli to:
- Change the protein’s final amino acid sequence
- Account for the different frequency of tRNA usage between humans and bacteria
- Add post-translational modifications
- Make the resulting protein insoluble
Answer: Account for the different frequency of tRNA usage between humans and bacteria
37. Recombinant vaccines (subunit vaccines) are often considered safer than live-attenuated vaccines because:
- They contain the entire live pathogen
- They contain only a specific antigen (protein) from the pathogen, with no risk of causing infection
- They are not effective at stimulating an immune response
- They are easier to administer orally
Answer: They contain only a specific antigen (protein) from the pathogen, with no risk of causing infection
38. Which technique would be most appropriate for removing endotoxins from a final protein preparation?
- Autoclaving
- Ion-exchange chromatography
- Gel filtration
- Filtration through a 0.22-micron filter
Answer: Ion-exchange chromatography
39. When a patient develops neutralizing antibodies to a recombinant protein therapy, the clinical result is often:
- An enhanced therapeutic effect
- A loss of therapeutic effect
- No change in the drug’s activity
- A switch in the drug’s mechanism of action
Answer: A loss of therapeutic effect
40. The production of recombinant proteins in the milk of transgenic goats is an example of:
- A microbial fermentation system
- A mammalian cell culture system
- A whole-animal bioreactor system
- A chemical synthesis method
Answer: A whole-animal bioreactor system
41. Which of the following is NOT a recombinant protein?
- Aspirin
- Humalog® (insulin lispro)
- Epogen® (epoetin alfa)
- Remicade® (infliximab)
Answer: Aspirin
42. The process of refolding a denatured protein recovered from an inclusion body is often a major challenge in:
- Downstream processing from bacterial systems
- Upstream processing in mammalian cells
- The formulation of the final product
- The administration to the patient
Answer: Downstream processing from bacterial systems
43. Aseptic technique is most critical during which stage of biopharmaceutical manufacturing?
- Gene sequencing
- Cell culture and fermentation
- Data analysis of clinical trials
- Marketing and sales
Answer: Cell culture and fermentation
44. What is the mechanism of action of denosumab, a recombinant monoclonal antibody?
- It stimulates red blood cell production
- It inhibits RANKL, a protein involved in bone resorption, to treat osteoporosis
- It neutralizes tumor necrosis factor-alpha (TNF-α)
- It dissolves blood clots
Answer: It inhibits RANKL, a protein involved in bone resorption, to treat osteoporosis
45. Compared to small molecule drugs, recombinant proteins are typically:
- Smaller in size and more stable
- Larger, more complex, and more sensitive to environmental conditions
- Administered orally
- Cleared exclusively by the kidneys
Answer: Larger, more complex, and more sensitive to environmental conditions
46. Ion-exchange chromatography separates proteins based on their:
- Size
- Net surface charge
- Affinity for a specific ligand
- Hydrophobicity
Answer: Net surface charge
47. A “signal peptide” is often engineered into the start of a recombinant protein’s sequence to:
- Keep the protein inside the cell
- Direct the protein to be secreted out of the host cell
- Make the protein bind to a purification column
- Cause the protein to misfold into an inclusion body
Answer: Direct the protein to be secreted out of the host cell
48. Why is it not possible to create a “generic” version of a recombinant protein in the same way as a small molecule drug?
- Because patents on biologics never expire
- Because the complex manufacturing process cannot be replicated exactly, leading to a “biosimilar” instead
- Because small molecule drugs are more effective
- Because pharmacists are not allowed to substitute them
Answer: Because the complex manufacturing process cannot be replicated exactly, leading to a “biosimilar” instead
49. What is a primary role of a pharmacist in managing patients on recombinant protein therapies?
- To adjust the patient’s DNA
- To educate the patient on proper injection technique, storage, and potential side effects
- To manufacture the protein in the pharmacy
- To decide which gene to clone for the next therapy
Answer: To educate the patient on proper injection technique, storage, and potential side effects
50. The future of recombinant protein technology is likely to involve:
- Less specific and less potent molecules
- A move away from all biological drugs
- More sophisticated engineering for better targeting, longer half-life, and novel functions
- A return to using only animal-derived insulin
Answer: More sophisticated engineering for better targeting, longer half-life, and novel functions
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.
Mail- Sachin@pharmacyfreak.com