MCQ Quiz- Protein Synthesis and Translational Control

MCQ Quiz: Protein Synthesis and Translational Control

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Protein synthesis, or translation, is the final step in the central dogma where the genetic code carried by mRNA is decoded to build a functional protein. This intricate process, orchestrated by the ribosome, is a major point of gene regulation and a key target for many essential drugs, especially antibiotics. For PharmD students, a firm grasp of translation is vital for understanding both normal physiology and the mechanisms of pharmacotherapy. This quiz will test your knowledge of the machinery, processes, and control of protein synthesis in both prokaryotes and eukaryotes.

1. “Translation” is the process in which the genetic information in ________ is used to synthesize a ________.

  • DNA; protein
  • RNA; DNA
  • mRNA; protein
  • protein; mRNA

Answer: mRNA; protein

2. The cellular machinery responsible for carrying out protein synthesis is the:

  • Nucleus
  • Mitochondrion
  • Ribosome
  • Spliceosome

Answer: The Ribosome

3. A three-nucleotide sequence on an mRNA molecule that specifies a particular amino acid is called a(n):

  • Gene
  • Intron
  • Exon
  • Codon

Answer: Codon

4. The molecule that acts as the “adaptor” between the mRNA codon and the corresponding amino acid is:

  • ribosomal RNA (rRNA)
  • small nuclear RNA (snRNA)
  • transfer RNA (tRNA)
  • messenger RNA (mRNA)

Answer: transfer RNA (tRNA)

5. The enzyme responsible for “charging” a tRNA molecule by attaching the correct amino acid is called:

  • RNA polymerase
  • Peptidyl transferase
  • Aminoacyl-tRNA synthetase
  • DNA ligase

Answer: Aminoacyl-tRNA synthetase

6. The “Wobble Hypothesis” explains why:

  • The genetic code is ambiguous.
  • Some tRNA molecules can recognize more than one codon.
  • Ribosomes can bind to any part of the mRNA.
  • Transcription and translation are coupled in eukaryotes.

Answer: Some tRNA molecules can recognize more than one codon.

7. Prokaryotic ribosomes are described as 70S and are composed of which two subunits?

  • 40S and 20S
  • 50S and 30S
  • 60S and 40S
  • 50S and 20S

Answer: 50S and 30S

8. Eukaryotic ribosomes are described as 80S and are composed of which two subunits?

  • 50S and 30S
  • 60S and 40S
  • 70S and 10S
  • 50S and 30S

Answer: 60S and 40S

9. In prokaryotic translation initiation, the small ribosomal subunit binds to a specific sequence on the mRNA just upstream of the start codon. This sequence is called the:

  • TATA box
  • Promoter
  • Shine-Dalgarno sequence
  • Poly(A) tail

Answer: Shine-Dalgarno sequence

10. The first amino acid in virtually all newly synthesized prokaryotic proteins is:

  • Methionine
  • N-formylmethionine (fMet)
  • Alanine
  • Glycine

Answer: N-formylmethionine (fMet)

11. The ribosome has three distinct sites for tRNA binding. The site where the charged tRNA first enters is the:

  • A (aminoacyl) site
  • P (peptidyl) site
  • E (exit) site
  • T (translocation) site

Answer: A (aminoacyl) site

12. The enzymatic activity that catalyzes the formation of the peptide bond between amino acids is performed by:

  • A protein enzyme in the large subunit.
  • The ribosomal RNA (rRNA) of the large subunit, acting as a ribozyme.
  • The mRNA itself.
  • An initiation factor.

Answer: The ribosomal RNA (rRNA) of the large subunit, acting as a ribozyme.

13. The process of the ribosome moving one codon down the mRNA strand is called:

  • Initiation
  • Termination
  • Translocation
  • Elongation

Answer: Translocation

14. Translation is terminated when the ribosome encounters a ________ on the mRNA.

  • Start codon
  • Promoter
  • Stop codon (UAA, UAG, UGA)
  • Intron

Answer: Stop codon (UAA, UAG, UGA)

15. Stop codons are recognized by proteins called:

  • Initiation factors
  • Elongation factors
  • Release factors
  • Sigma factors

Answer: Release factors

16. How does initiation of translation in eukaryotes primarily differ from prokaryotes?

  • Eukaryotic ribosomes recognize a Shine-Dalgarno sequence.
  • Eukaryotic translation is coupled with transcription.
  • The eukaryotic small ribosomal subunit typically binds at the 5′ cap and scans downstream to find the first AUG.
  • Eukaryotes use N-formylmethionine as the first amino acid.

Answer: The eukaryotic small ribosomal subunit typically binds at the 5′ cap and scans downstream to find the first AUG.

17. The “Kozak sequence” is a consensus sequence in ________ that helps the ribosome identify the correct start codon.

  • Prokaryotes
  • Eukaryotes
  • Both prokaryotes and eukaryotes
  • Viruses

Answer: Eukaryotes

18. Many antibiotics, like tetracycline and erythromycin, are effective because they:

  • Inhibit eukaryotic protein synthesis.
  • Selectively inhibit prokaryotic protein synthesis by targeting the bacterial ribosome.
  • Inhibit bacterial DNA replication.
  • Disrupt the bacterial cell wall.

Answer: Selectively inhibit prokaryotic protein synthesis by targeting the bacterial ribosome.

19. Tetracycline works by:

  • Blocking the A site on the 30S ribosomal subunit.
  • Inhibiting peptidyl transferase.
  • Preventing translocation.
  • Causing premature termination.

Answer: Blocking the A site on the 30S ribosomal subunit.

20. Macrolide antibiotics like azithromycin work by:

  • Binding to the 30S subunit.
  • Binding to the 50S subunit and blocking the exit tunnel, inhibiting elongation.
  • Inhibiting the charging of tRNA.
  • Blocking the Shine-Dalgarno sequence.

Answer: Binding to the 50S subunit and blocking the exit tunnel, inhibiting elongation.

21. “Translational control” refers to the regulation of:

  • The rate of transcription.
  • The rate at which an mRNA is translated into protein.
  • The process of DNA repair.
  • The splicing of pre-mRNA.

Answer: The rate at which an mRNA is translated into protein.

22. A major point of global translational control in eukaryotes is the phosphorylation of the initiation factor ________, which is often a response to cellular stress.

  • eIF1
  • eIF2
  • eIF3
  • eIF4E

Answer: eIF2

23. Phosphorylation of eIF2 leads to a general ________ in protein synthesis.

  • Increase
  • Decrease
  • It has no effect
  • A switch to prokaryotic-style initiation

Answer: Decrease

24. MicroRNAs (miRNAs) are small non-coding RNAs that can control translation by:

  • Binding to the promoter of a gene.
  • Binding to a target mRNA, leading to its degradation or the repression of its translation.
  • Modifying histone tails.
  • Adding a poly(A) tail to the mRNA.

Answer: Binding to a target mRNA, leading to its degradation or the repression of its translation.

25. A pharmacist’s knowledge of the “Eukaryotic and Prokaryotic Transcription” process is the foundation for understanding how:

  • The mRNA template for translation is created.
  • DNA is replicated.
  • The genetic code was first discovered.
  • Proteins are folded.

Answer: The mRNA template for translation is created.

26. The principle of “Eukaryotic RNA processing” (capping, splicing, polyadenylation) is critical for creating a:

  • Stable and translatable eukaryotic mRNA molecule.
  • Prokaryotic mRNA molecule.
  • Transfer RNA molecule.
  • Ribosomal RNA molecule.

Answer: Stable and translatable eukaryotic mRNA molecule.

27. The genetic code is described as “degenerate” or “redundant.” This means that:

  • Each codon can specify more than one amino acid.
  • An amino acid can be specified by more than one codon.
  • The code is different in prokaryotes and eukaryotes.
  • There are no stop codons.

Answer: An amino acid can be specified by more than one codon.

28. A “frameshift” mutation is a genetic alteration that:

  • Changes a single amino acid.
  • Inserts or deletes a number of nucleotides that is not a multiple of three, altering the reading frame of the ribosome.
  • Has no effect on the final protein.
  • Occurs in a non-coding region.

Answer: Inserts or deletes a number of nucleotides that is not a multiple of three, altering the reading frame of the ribosome.

29. The “anticodon” is a three-nucleotide sequence found on a(n):

  • mRNA molecule
  • tRNA molecule
  • rRNA molecule
  • DNA molecule

Answer: tRNA molecule

30. The ultimate reason pharmacists study protein synthesis is that:

  • It is the final step in expressing the genetic information that produces drug targets (receptors, enzymes).
  • The ribosome is a major target for many important antibiotics.
  • Dysregulation of translation is a hallmark of many diseases, like cancer.
  • All of the above.

Answer: All of the above.

31. The “forging ahead” mindset in pharmacy means understanding how new drugs, like RNAi therapies, can work by:

  • Modulating translation.
  • Inhibiting DNA replication.
  • Repairing damaged DNA.
  • Changing the genetic code.

Answer: Modulating translation.

32. A “business plan” for a new antibiotic would need to detail its mechanism of action, which could be the inhibition of:

  • Eukaryotic translation.
  • Prokaryotic translation.
  • The host cell’s DNA polymerase.
  • The human immune system.

Answer: Prokaryotic translation.

33. The “regulation” of antibiotics that target the ribosome is a key part of:

  • Antimicrobial stewardship, to prevent the development of resistance.
  • Pharmacy marketing.
  • Financial management.
  • Human resources.

Answer: Antimicrobial stewardship, to prevent the development of resistance.

34. The use of “analytics and reporting systems” in a hospital can help an antimicrobial stewardship pharmacist track:

  • The usage rates of antibiotics that target protein synthesis.
  • The local resistance patterns for these antibiotics.
  • Both A and B.
  • Neither A nor B.

Answer: Both A and B.

35. A “Clinical Decision Support” system could be designed to alert a pharmacist if a patient is prescribed two antibiotics that both target the 50S ribosomal subunit, as this could be a sign of:

  • A synergistic combination.
  • A therapeutic duplication or antagonistic interaction.
  • The best possible therapy.
  • A requirement for a genetic test.

Answer: A therapeutic duplication or antagonistic interaction.

36. The “leadership” skill of interprofessional communication is critical when a pharmacist needs to discuss:

  • An antibiotic’s mechanism of action with a physician to recommend a better therapy.
  • The pharmacy’s budget.
  • The schedule for the technicians.
  • The price of a medication.

Answer: An antibiotic’s mechanism of action with a physician to recommend a better therapy.

37. The “enzymes of DNA metabolism” are crucial for making the DNA template, which is then transcribed into RNA, and that RNA is then ________ into protein.

  • Replicated
  • Repaired
  • Translated
  • Mutated

Answer: Translated

38. The “molecular biology technique” of creating a recombinant protein like insulin involves:

  • Cloning the gene into a vector.
  • Transforming a host cell (like E. coli).
  • Inducing the host cell to transcribe and translate the gene into protein.
  • All of the above.

Answer: All of the above.

39. A key “policy” issue in global health is the need for new antibiotics that target novel sites on the bacterial:

  • Ribosome or other essential machinery.
  • Human cell membrane.
  • Eukaryotic ribosome.
  • Mitochondria.

Answer: Ribosome or other essential machinery.

40. A “health disparity” could arise if a new, expensive antibiotic that targets a resistant bacterium’s ribosome is:

  • Made available to all patients at a low cost.
  • So expensive that it is only accessible to patients in wealthy hospitals.
  • Covered by government insurance programs.
  • Easy to manufacture.

Answer: So expensive that it is only accessible to patients in wealthy hospitals.

41. The binding of a charged tRNA to the A site of the ribosome is facilitated by which protein factor and energy source?

  • An initiation factor and ATP.
  • An elongation factor (EF-Tu in prokaryotes) and GTP.
  • A release factor and ATP.
  • A sigma factor and GTP.

Answer: An elongation factor (EF-Tu in prokaryotes) and GTP.

42. The “A” in the “START” codon (AUG) stands for:

  • Alanine
  • Aspartate
  • Adenine
  • Arginine

Answer: Adenine

43. A pharmacist’s knowledge of “human factors” is relevant to preventing errors with antibiotics that target protein synthesis, such as:

  • Ensuring correct dosing for aminoglycosides to prevent toxicity.
  • Using “tall man” lettering for look-alike/sound-alike names.
  • Designing a safe workflow for preparing IV antibiotics.
  • All of the above.

Answer: All of the above.

44. “Translational frameshifting” is a rare phenomenon where:

  • The ribosome shifts its reading frame by a number of nucleotides other than three, creating a different protein.
  • The ribosome skips the start codon.
  • The ribosome reads through a stop codon.
  • The mRNA is spliced incorrectly.

Answer: The ribosome shifts its reading frame by a number of nucleotides other than three, creating a different protein.

45. A “polysome” or “polyribosome” is a structure consisting of:

  • A single ribosome translating a single mRNA.
  • Multiple ribosomes simultaneously translating the same mRNA molecule.
  • A ribosome bound to a DNA molecule.
  • An mRNA molecule that has not yet been processed.

Answer: Multiple ribosomes simultaneously translating the same mRNA molecule.

46. The “services” a pharmacist provides, such as MTM, often involve reviewing a patient’s entire regimen to identify potential issues, such as:

  • A drug interaction affecting an antibiotic that targets the ribosome.
  • The need for an antibiotic.
  • A duplication of therapy with two different macrolides.
  • Both A and C.

Answer: Both A and C.

47. A pharmacist’s role in “drug use and prevention” is relevant because the overuse of antibiotics that target the ribosome leads to:

  • The development of antimicrobial resistance.
  • An increase in their efficacy.
  • A decrease in their cost.
  • No significant public health problems.

Answer: The development of antimicrobial resistance.

48. In which “practice setting” is a pharmacist most likely to be involved in dosing an aminoglycoside, which targets the ribosome, based on therapeutic drug monitoring?

  • A community pharmacy.
  • A hospital/institutional setting.
  • A mail-order pharmacy.
  • A supermarket pharmacy.

Answer: A hospital/institutional setting.

49. An “Electronic Health Record” (EHR) can support the safe use of protein synthesis inhibitors by:

  • Providing a clear record of a patient’s allergies.
  • Alerting a prescriber to a potential drug-drug interaction.
  • Displaying a patient’s renal function for dose adjustments.
  • All of the above.

Answer: All of the above.

50. The ultimate principle of why pharmacists study translation is because this fundamental process is:

  • A primary target for a large and important class of antibiotics and a key control point in many human diseases.
  • An interesting but clinically minor topic.
  • The same in all forms of life, with no differences.
  • Only relevant for understanding genetic mutations.

Answer: A primary target for a large and important class of antibiotics and a key control point in many human diseases.

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