$$\text{Amino acid} + \text{tRNA} + \text{ATP} \rightarrow \text{Aminoacyl-tRNA} + \text{AMP} + \text{PP}_i$$

Question 1

Which of the following best describes the role of the Shine-Dalgarno sequence in prokaryotic translation initiation?

Accepted Answer

It base-pairs with the 3' end of 16S rRNA to align the start codon in the P site of the ribosome.

Question 2

A new antibiotic is found to inhibit the function of EF-G in bacteria. What step of translation would be directly affected?

Accepted Answer

Translocation of the ribosome along the mRNA

Question 3

Which of the following statements correctly compares the first amino acid incorporated during translation in prokaryotes and eukaryotes?

Accepted Answer

Prokaryotes use N-formylmethionine, while eukaryotes use methionine.

Question 4

During translation elongation in eukaryotes, which elongation factor is responsible for delivering aminoacyl-tRNA to the A site of the ribosome?

Accepted Answer

eEF1A

Question 5

A mutation in the gene encoding the 16S rRNA in bacteria would most likely disrupt which process?

Accepted Answer

Recognition of the Shine-Dalgarno sequence during translation initiation

Question 6

Which of the following is a key difference between translation initiation in prokaryotes and eukaryotes?

Accepted Answer

Eukaryotes use a Kozak sequence for start codon recognition, while prokaryotes use a Shine-Dalgarno sequence.

Question 7

Which of the following antibiotics specifically inhibits bacterial RNA polymerase, thereby blocking transcription?

Accepted Answer

Rifampicin

Question 8

What is the function of aminoacyl-tRNA synthetase in translation?

Accepted Answer

It attaches the correct amino acid to its corresponding tRNA using ATP.

Question 9

Which of the following equations correctly represents the energy requirement for the attachment of an amino acid to tRNA?

Accepted Answer

$$	ext{Amino acid} + 	ext{tRNA} + 	ext{ATP} ightarrow 	ext{Aminoacyl-tRNA} + 	ext{AMP} + 	ext{PP}_i$$

Question 10

A patient is treated with an antibiotic that binds to the 50S subunit of the bacterial ribosome. Which process is most likely to be inhibited?

Accepted Answer

Peptide bond formation during translation

Question 11

Which of the following best explains why tetracyclines are effective antibiotics against bacteria but not harmful to human cells?

Accepted Answer

Tetracyclines bind specifically to the 70S ribosome found only in bacteria, not the 80S ribosome of eukaryotes.

Question 12

Which of the following is the correct order of events during translation elongation in prokaryotes?

Accepted Answer

Codon recognition → Peptide bond formation → Translocation

Question 13

A mutation eliminates the function of eRF1 in eukaryotic cells. What is the most likely consequence?

Accepted Answer

The ribosome will fail to recognize stop codons, resulting in abnormally long polypeptides.

Question 14

Which of the following features is unique to eukaryotic mRNA and is essential for efficient translation initiation?

Accepted Answer

5' cap structure (m⁷G cap)

Question 15

In prokaryotic translation termination, which release factor recognizes both UAA and UGA stop codons?

Accepted Answer

RF2

Question 16

Which of the following best describes the role of GTP hydrolysis during translation?

Accepted Answer

It provides energy for several steps, including initiation, elongation, and termination.

Question 17

A researcher is studying a eukaryotic mRNA with a mutation that disrupts the Kozak sequence. What is the most likely effect on translation?

Accepted Answer

Translation initiation efficiency will decrease due to poor recognition of the start codon.

Question 18

Which of the following correctly matches the ribosomal subunits with their respective organisms?

Accepted Answer

Prokaryotes: 30S + 50S; Eukaryotes: 40S + 60S

Question 19

Which of the following is a post-translational modification that newly synthesized proteins may undergo before becoming fully functional?

Accepted Answer

Phosphorylation

(W3 L1) Translation: Mechanisms and Comparison in Prokaryotes and Eukaryotes

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