Q: Which equation correctly represents the reaction catalyzed by aminoacyl tRNA synthetase?

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

Q: Which equation best represents the dehydration reaction forming a peptide bond between two amino acids?

$$\text{Amino acid}_1 + \text{Amino acid}_2 \rightarrow \text{Dipeptide} + \text{H}_2\text{O}$$

Question 1

Which of the following best describes the role of aminoacyl tRNA synthetase in translation?

Accepted Answer

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

Question 2

A mutation causes a tRNA for valine to be charged with glycine instead. What is the most likely outcome during translation?

Accepted Answer

Glycine will be incorporated at all valine codons.

Question 3

Which equation correctly represents the reaction catalyzed by aminoacyl tRNA synthetase?

Accepted Answer

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

Question 4

Which ribosomal RNA is responsible for catalyzing peptide bond formation during translation in bacteria?

Accepted Answer

23S rRNA

Question 5

In eukaryotic translation, what is the function of the Kozak sequence?

Accepted Answer

It increases the efficiency of translation initiation.

Question 6

Which of the following is NOT a function of proteins in cells?

Accepted Answer

Storing genetic information

Question 7

A polypeptide chain is synthesized from the N-terminus to the C-terminus. Which site on the ribosome does the incoming aminoacyl-tRNA enter during elongation?

Accepted Answer

A site

Question 8

Which of the following best explains why eukaryotic mRNAs are translated in a 'closed loop' structure?

Accepted Answer

It prevents translation of partially degraded mRNA and enables ribosome recycling.

Question 9

Which of the following diseases is associated with misfolded proteins known as prions?

Accepted Answer

Creutzfeldt–Jakob disease

Question 10

Which level of protein structure is directly determined by the sequence of amino acids?

Accepted Answer

Primary structure

Question 11

Which equation best represents the dehydration reaction forming a peptide bond between two amino acids?

Accepted Answer

$$	ext{Amino acid}_1 + 	ext{Amino acid}_2 ightarrow 	ext{Dipeptide} + 	ext{H}_2	ext{O}$$

Question 12

Which of the following statements about polyribosomes (polysomes) is correct?

Accepted Answer

They allow multiple ribosomes to translate a single mRNA simultaneously.

Question 13

Which protein factor is responsible for catalyzing the release of the polypeptide chain from tRNA during translation termination in E. coli?

Accepted Answer

RF1

Question 14

A Neurospora mutant grows on minimal medium supplemented with purines but not with pyrimidines or amino acids. What is the most likely auxotrophy?

Accepted Answer

Auxotrophic for purines

Question 15

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

Accepted Answer

Eukaryotic ribosomes are larger and translation is initiated by a 5' cap and poly-A tail.

Question 16

Which of the following best describes the 'one-gene:one-polypeptide chain' hypothesis?

Accepted Answer

Each gene codes for a single polypeptide chain, which may be part of a protein.

Question 17

Which of the following statements about tRNA structure is correct?

Accepted Answer

The anticodon loop pairs with the mRNA codon, and the amino acid is attached at the 3' end.

Question 18

Which of the following protein domains is most likely to be found in a transcription factor?

Accepted Answer

DNA binding domain

Question 19

Which of the following is a function of chaperone proteins?

Accepted Answer

They mediate the folding of newly synthesized polypeptides.

Question 20

Which equation best represents the energy requirement for elongation during translation?

Accepted Answer

$$	ext{Aminoacyl-tRNA} + 	ext{GTP} ightarrow 	ext{Peptide bond} + 	ext{GDP} + 	ext{P}_i$$

Ch 13 Translation and Proteins: From mRNA to Functional Polypeptides

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