Question 1

Which of the following statements best describes the 'wobble hypothesis' in the context of tRNA and codon recognition?

Accepted Answer

The first two bases of the codon and anticodon pair strictly, but the third base can form non-standard base pairs, allowing one tRNA to recognize multiple codons.

Question 2

A mutation changes the codon UAU (tyrosine) to UAA in an mRNA sequence. What is the most likely consequence of this mutation during translation?

Accepted Answer

Translation will terminate prematurely because UAA is a stop codon.

Question 3

Which of the following best explains why there are only about 30 different tRNA species, even though there are 61 codons that specify amino acids?

Accepted Answer

The wobble at the third codon position allows some tRNAs to recognize more than one codon.

Question 4

In prokaryotes, which sequence on the mRNA is recognized by the small ribosomal subunit to initiate translation?

Accepted Answer

Shine-Dalgarno sequence

Question 5

Which of the following is NOT a function of aminoacyl tRNA synthetase?

Accepted Answer

Catalyzing the formation of peptide bonds between amino acids during elongation

Question 6

A researcher mutates the start codon (AUG) of a bacterial gene to UUG. What is the most likely effect on translation?

Accepted Answer

Translation initiation will be severely impaired or not occur, as AUG is required for initiation.

Question 7

Which of the following best describes the primary structure of a protein?

Accepted Answer

The linear sequence of amino acids joined by peptide bonds from the amino terminus to the carboxy terminus

Question 8

During translation elongation, which site on the ribosome does the charged tRNA first enter?

Accepted Answer

A (aminoacyl) site

Question 9

Which of the following statements about translation in eukaryotes is TRUE?

Accepted Answer

Translation occurs in the cytoplasm, and many ribosomes are associated with the endoplasmic reticulum.

Question 10

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

Accepted Answer

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

Question 11

A patient has a mutation in a gene encoding a ribosomal protein that impairs the formation of the large ribosomal subunit. Which process will be most directly affected?

Accepted Answer

Peptide bond formation during translation

Question 12

Which of the following is a post-translational modification that can occur to a newly synthesized polypeptide?

Accepted Answer

Folding into a three-dimensional structure

Question 13

Which of the following codons is a stop codon in the genetic code?

Accepted Answer

UGA

Question 14

In eukaryotes, which sequence is analogous to the Shine-Dalgarno sequence in prokaryotes for efficient translation initiation?

Accepted Answer

Kozak sequence

Question 15

Which of the following best describes the secondary structure of a protein?

Accepted Answer

Regular folding patterns such as alpha helices and beta sheets stabilized by hydrogen bonds

Question 16

A charged tRNA is defined as:

Accepted Answer

A tRNA molecule covalently linked to its specific amino acid

Question 17

Which of the following is a key difference between prokaryotic and eukaryotic translation?

Accepted Answer

In prokaryotes, translation can begin before transcription is complete; in eukaryotes, transcription and translation are separated by the nuclear envelope.

Question 18

Which of the following best describes the quaternary structure of a protein?

Accepted Answer

The association of two or more polypeptide chains to form a functional protein complex

Question 19

During translation, what is the role of the peptidyl transferase activity of the ribosome?

Accepted Answer

It catalyzes the formation of peptide bonds between amino acids.

Question 20

A patient is diagnosed with a genetic disorder that affects the function of release factors during translation. What is the most likely cellular consequence?

Accepted Answer

Polypeptide chains will not be properly released from the ribosome at stop codons, leading to stalled ribosomes.

Translation and Proteins: Genetic Code, tRNA, Ribosomes, and Protein Structure

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