Question 1

Which of the following best explains why transcription and translation can be coupled in bacteria but not in eukaryotes?

Accepted Answer

Bacteria lack a nucleus, allowing ribosomes to access mRNA as it is being transcribed.

Question 2

What is the function of the anticodon region of a tRNA molecule?

Accepted Answer

It base-pairs with the complementary codon on the mRNA.

Question 3

A mutation in the gene encoding an aminoacyl-tRNA synthetase results in the enzyme attaching the wrong amino acid to a tRNA. What is the most likely consequence?

Accepted Answer

Proteins will be synthesized with incorrect amino acids, potentially altering their function.

Question 4

Which of the following statements about wobble pairing is correct?

Accepted Answer

It allows a single tRNA to recognize multiple codons due to flexible base pairing at the third codon position.

Question 5

During translation elongation, what is the correct order of events?

Accepted Answer

Aminoacyl tRNA enters the A site, peptide bond forms, ribosome translocates.

Question 6

Which site on the ribosome does the initiator tRNA occupy at the start of translation in bacteria?

Accepted Answer

P site

Question 7

What is the role of the release factor during translation termination?

Accepted Answer

It binds to the stop codon in the A site and hydrolyzes the bond between the polypeptide and tRNA.

Question 8

Which of the following best describes the function of molecular chaperones in protein synthesis?

Accepted Answer

They assist in the proper folding of newly synthesized polypeptides.

Question 9

A scientist observes that a certain protein is not functional unless a phosphate group is added after translation. This is an example of:

Accepted Answer

Post-translational modification

Question 10

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

Accepted Answer

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

Question 11

Which of the following is true regarding the ribosome’s catalytic activity?

Accepted Answer

The ribosome is a ribozyme because its catalytic activity is due to rRNA.

Question 12

In a bacterial cell, which sequence is recognized by the small ribosomal subunit to initiate translation?

Accepted Answer

Shine–Dalgarno sequence

Question 13

If a mutation prevents the addition of the CCA sequence at the 3' end of tRNA, what is the most likely outcome?

Accepted Answer

The tRNA will not be able to attach an amino acid.

Question 14

Which of the following best describes the direction in which a polypeptide is synthesized?

Accepted Answer

From the amino (N) terminus to the carboxyl (C) terminus

Question 15

A researcher adds a molecule that mimics the shape of tRNA but cannot carry an amino acid. What is the most likely effect if this molecule enters the A site during translation?

Accepted Answer

Translation will terminate because the release factor mimics tRNA and causes hydrolysis of the polypeptide.

Question 16

Which of the following steps is NOT part of the elongation phase of translation?

Accepted Answer

Binding of the large ribosomal subunit to the initiation complex

Question 17

Which of the following modifications can occur to a protein after translation to regulate its activity?

Accepted Answer

Addition of a phosphate group

Question 18

A mutation causes a stop codon to appear prematurely in an mRNA. What is the most likely result?

Accepted Answer

A truncated, likely nonfunctional protein will be produced.

Question 19

Which of the following best explains why there are fewer tRNAs than codons?

Accepted Answer

Wobble pairing allows some tRNAs to recognize more than one codon.

Question 20

Which of the following is a direct result of the separation of transcription and translation in eukaryotic cells?

Accepted Answer

mRNA processing can occur before translation begins.

Transcription, RNA Processing, and Translation: Structure and Function

Study Guide - Practice Questions

Study Guide - Flashcards