Question 1

Which of the following best describes the role of the ribosome during translation?

Accepted Answer

It catalyzes the formation of peptide bonds between amino acids and decodes codons on mRNA.

Question 2

Aminoacyl-tRNA synthetase is responsible for which of the following steps in protein synthesis?

Accepted Answer

Attaching a specific amino acid to the 3'OH end of its corresponding tRNA using ATP.

Question 3

During translation elongation, what is the correct order of tRNA movement through the ribosome's binding sites?

Accepted Answer

A site → P site → E site

Question 4

Which of the following statements about the wobble hypothesis is correct?

Accepted Answer

The third base of the codon and the first base of the anticodon do not pair strongly, allowing one tRNA to recognize multiple codons.

Question 5

A mutation changes a codon from UAU (tyrosine) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 6

Which energy molecule is used by EF-Tu to lock charged tRNA into the A site of the ribosome during elongation?

Accepted Answer

GTP

Question 7

What is the consequence of a frameshift mutation in a gene?

Accepted Answer

It alters the reading frame, potentially changing every amino acid downstream of the mutation.

Question 8

In prokaryotes, the ribosome binds to the mRNA at which specific sequence during translation initiation?

Accepted Answer

Shine-Dalgarno sequence

Question 9

Which of the following best explains why the genetic code is described as 'degenerate'?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 10

A tRNA molecule with the anticodon 5'-UAC-3' will pair with which mRNA codon?

Accepted Answer

5'-AUG-3'

Question 11

Which of the following is TRUE regarding the structure of eukaryotic and prokaryotic ribosomes?

Accepted Answer

Eukaryotic ribosomes are 80S, while prokaryotic ribosomes are 70S.

Question 12

During translation termination, what causes the ribosome to dissociate and release the polypeptide chain?

Accepted Answer

Release factors recognize the stop codon and trigger dissociation.

Question 13

Which of the following steps in translation requires the hydrolysis of ATP?

Accepted Answer

Attachment of amino acid to tRNA by aminoacyl-tRNA synthetase.

Question 14

A silent mutation most commonly occurs when:

Accepted Answer

A base substitution changes the codon but does not alter the amino acid sequence.

Question 15

Which of the following best describes the function of the signal recognition particle (SRP) in protein synthesis?

Accepted Answer

SRP binds the ribosome and delivers it to the rough endoplasmic reticulum membrane.

Question 16

If a tRNA is charged with serine, which enzyme was responsible for this process?

Accepted Answer

Seryl-tRNA synthetase

Question 17

Which of the following is a direct result of a nonsense mutation in a gene?

Accepted Answer

A truncated protein due to premature translation termination.

Question 18

Which of the following correctly matches the ribosomal binding site with its function?

Accepted Answer

E site: tRNA exits the ribosome

Question 19

A patient has a mutation in the gene encoding EF-G. Which step of translation would be most directly affected?

Accepted Answer

Translocation of the ribosome to the next codon

Question 20

Which of the following equations correctly represents the energy requirement for charging a tRNA with an amino acid?

Accepted Answer

$$\mathrm{Amino~acid} + \mathrm{tRNA} + \mathrm{ATP} \rightarrow \mathrm{Aminoacyl{-}tRNA} + \mathrm{AMP} + \mathrm{PP_i}$$

Translation, tRNA, Ribosomes, and Mutations in Protein Synthesis

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