Question 1

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

Accepted Answer

It decodes codons on mRNA and forms peptide bonds between amino acids.

Question 2

A charged tRNA molecule is defined as:

Accepted Answer

A tRNA that is covalently bound to its specific amino acid at the 3' end.

Question 3

During translation elongation, which factor uses GTP to move the ribosome to the next codon?

Accepted Answer

EF-G

Question 4

Which statement about the wobble hypothesis is correct?

Accepted Answer

The first base of the codon and the third 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 of the following equations correctly represents the energy requirement for attaching an amino acid to tRNA?

Accepted Answer

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

Question 7

In prokaryotes, the ribosome recognizes the start site of translation by binding to which sequence?

Accepted Answer

Shine-Dalgarno sequence

Question 8

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

Accepted Answer

Eukaryotic ribosomes are composed of 60S and 40S subunits.

Question 9

A frameshift mutation is most likely to occur when:

Accepted Answer

One or two nucleotides are inserted or deleted, altering the reading frame.

Question 10

Which process ensures that the correct amino acid is attached to the correct tRNA?

Accepted Answer

Aminoacyl-tRNA synthetase recognizing the tRNA's anticodon

Question 11

During translation, which site on the ribosome does the incoming charged tRNA first bind?

Accepted Answer

A site

Question 12

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 13

What is the consequence of a silent mutation in a coding region of DNA?

Accepted Answer

It does not change the amino acid sequence of the protein.

Question 14

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

Accepted Answer

Translocation of the ribosome to the next codon

Question 15

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

Accepted Answer

5'-AUG-3'

Question 16

Which of the following is a function of the signal recognition particle (SRP) during protein synthesis?

Accepted Answer

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

Question 17

If the mRNA sequence is 5'-AUGGCUUAA-3', what is the resulting amino acid sequence?

Accepted Answer

Met-Ala-Stop

Question 18

Which of the following statements about translation termination is correct?

Accepted Answer

Release factors bind to the stop codon, causing the ribosome to dissociate and release the polypeptide.

Question 19

Which of the following best describes the direction in which the ribosome moves along the mRNA during translation?

Accepted Answer

5' to 3'

Question 20

A patient has a mutation in the gene encoding EF-Tu. Which process would be most directly affected?

Accepted Answer

Delivery and tight binding of charged tRNA to the A site of the ribosome

Translation, tRNA, Ribosomes, and Mutations in Protein Synthesis

Guida di studio - Domande di pratica