$$\text{Amino acid} + \text{tRNA} + \text{ATP} \rightarrow \text{Aminoacyl-tRNA} + \text{AMP} + 2\text{P}_i$$

Question 1

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

Accepted Answer

tRNA carries amino acids to the ribosome and matches them to the mRNA codon via its anticodon.

Question 2

What is the function of aminoacyl-tRNA synthetase in translation?

Accepted Answer

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

Question 3

During translation, which site on the ribosome holds the tRNA carrying the growing polypeptide chain?

Accepted Answer

P site (peptidyl-tRNA binding site)

Question 4

Which of the following codons signals the termination of translation?

Accepted Answer

5'-UAA-3'

Question 5

In bacteria, translation can begin while transcription is still ongoing. What cellular feature allows this?

Accepted Answer

Absence of compartmentalization (no nucleus)

Question 6

Which equation represents the energy requirement for attaching an amino acid to tRNA?

Accepted Answer

$$	ext{Amino acid} + 	ext{tRNA} + 	ext{ATP} ightarrow 	ext{Aminoacyl-tRNA} + 	ext{AMP} + 2	ext{P}_i$$

Question 7

What is the significance of 'wobble' in tRNA anticodon-codon pairing?

Accepted Answer

It allows some tRNAs to bind to multiple codons that differ at the third base.

Question 8

Which molecule acts as a catalyst for peptide bond formation during translation?

Accepted Answer

Ribosomal RNA (rRNA)

Question 9

A polypeptide destined for secretion from a eukaryotic cell is targeted to the ER by:

Accepted Answer

A signal peptide recognized by a signal-recognition particle (SRP)

Question 10

Which of the following best describes the direction of polypeptide synthesis?

Accepted Answer

From the N-terminus (initial methionine) to the C-terminus (final amino acid)

Question 11

Which of the following is NOT a post-translational modification?

Accepted Answer

Transcription of DNA into mRNA

Question 12

What is the main difference between free and bound ribosomes in eukaryotic cells?

Accepted Answer

Free ribosomes synthesize proteins that remain in the cytosol, while bound ribosomes synthesize proteins for the endomembrane system or secretion.

Question 13

Which of the following statements about polyribosomes is correct?

Accepted Answer

Polyribosomes are clusters of ribosomes translating the same mRNA simultaneously.

Question 14

Which process requires the hydrolysis of GTP during translation?

Accepted Answer

Initiation, elongation, and termination steps of translation

Question 15

If a tRNA has the anticodon 3'-CCG-5', which mRNA codon will it bind to?

Accepted Answer

5'-GGC-3'

Question 16

Which of the following is a real-world application of antibiotics targeting translation?

Accepted Answer

Antibiotics like tetracycline inhibit bacterial ribosomes without affecting eukaryotic ribosomes.

Question 17

Which equation best represents the hydrolysis of GTP during the elongation cycle of translation?

Accepted Answer

$$	ext{GTP} ightarrow 	ext{GDP} + 	ext{P}_i$$

Question 18

Which statement about the ribosome's structure is correct?

Accepted Answer

The ribosome consists of a large and a small subunit, each made of proteins and rRNAs.

Question 19

What is the consequence of a mutation that changes the start codon (AUG) in an mRNA?

Accepted Answer

Translation may not initiate, leading to no polypeptide being produced.

Translation: The RNA-Directed Synthesis of Polypeptides

Study Guide - Practice Questions