Q: Which of the following equations correctly represents the overall reaction for charging a tRNA with its amino acid?

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

Question 1

Which of the following statements best describes the function of tRNA during translation?

Accepted Answer

tRNA carries specific amino acids to the ribosome and matches them to the codons in mRNA via its anticodon.

Question 2

The wobble hypothesis explains how:

Accepted Answer

A single tRNA can recognize multiple codons due to flexible base pairing at the third codon position.

Question 3

Which of the following is a correct sequence of events during the charging of a tRNA molecule?

Accepted Answer

Amino acid reacts with ATP to form aminoacyladenylic acid, which then binds to tRNA, forming charged tRNA.

Question 4

In bacteria, the Shine-Dalgarno sequence is important because it:

Accepted Answer

Aligns the ribosome with the start codon on mRNA by base pairing with 16S rRNA.

Question 5

Which of the following best describes the role of aminoacyl-tRNA synthetase?

Accepted Answer

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

Question 6

During translation elongation in bacteria, which event occurs immediately after the peptide bond is formed?

Accepted Answer

The ribosome translocates, moving the tRNA from the A site to the P site.

Question 7

Which of the following is true regarding the structure of mature tRNA molecules?

Accepted Answer

They are typically 75-90 nucleotides long and contain modified bases such as inosine and pseudouridine.

Question 8

A mutation in the gene encoding EF-Tu in E. coli would most directly affect which process?

Accepted Answer

The delivery of aminoacyl-tRNA to the A site during elongation.

Question 9

Which of the following equations correctly represents the overall reaction for charging a tRNA with its amino acid?

Accepted Answer

$$\mathrm{Amino\ acid} + \mathrm{tRNA} + \mathrm{ATP} ightarrow \mathrm{Aminoacyl	ext{-}tRNA} + \mathrm{AMP} + \mathrm{PP_i}$$

Question 10

Which of the following best explains why there are fewer than 61 different tRNA species in most cells?

Accepted Answer

Some tRNAs can recognize multiple codons due to nonstandard base pairing at the wobble position.

Question 11

In the context of translation, what is the primary function of the ribosomal RNA (rRNA) in the large subunit?

Accepted Answer

It catalyzes the formation of peptide bonds between amino acids.

Question 12

A patient is found to have a mutation that prevents the formation of the 5'-CCA-3' sequence at the 3' end of tRNA. What is the most likely consequence?

Accepted Answer

The tRNA will be unable to attach an amino acid, preventing its participation in translation.

Question 13

Which of the following correctly matches a translation factor with its function in E. coli?

Accepted Answer

IF2: Binds the initiator fMet-tRNA and transfers it to the P site of the 30S-mRNA complex.

Question 14

During translation termination in bacteria, which of the following events occurs first?

Accepted Answer

A stop codon enters the A site and is recognized by RF1 or RF2.

Question 15

Which of the following best describes the difference between prokaryotic and eukaryotic ribosomes?

Accepted Answer

Prokaryotic ribosomes are 70S, composed of 50S and 30S subunits, while eukaryotic ribosomes are 80S, composed of 60S and 40S subunits.

Question 16

A researcher mutates the Shine-Dalgarno sequence in a bacterial mRNA. What is the most likely effect on translation?

Accepted Answer

The ribosome will fail to align properly with the start codon, reducing translation efficiency.

Question 17

Which of the following is a real-world example of the importance of the wobble hypothesis?

Accepted Answer

It allows cells to use fewer tRNA genes to decode all possible codons, increasing efficiency and reducing the genetic load.

Question 18

Which of the following best describes the chemical bond formed during peptide bond formation in translation?

Accepted Answer

A bond between the carboxyl group of one amino acid and the amino group of the incoming amino acid.

Translation: Molecular Mechanisms and Components

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