Chapter 5 Mechanism of Translation (MBOG

What are the three stages of translation?

• A) Transcription, Initiation, Termination

• B) Initiation, Elongation, Termination

• C) Replication, Elongation, Termination

• D) Translation, Replication, Termination

What is the role of transfer RNAs (tRNAs) in translation?

• A) They serve as protein factories

• B) They initiate translation

• C) They extend the polypeptide chain

• D) They act as adapters that can bind an amino acid at one end and interact with the mRNA at the other

How many tRNA-binding sites does a ribosome have?

• A) 1

• B) 2

• C) 3

• D) 8

Which site of the ribosome does the aminoacyl-tRNA enter during elongation?

• A) A site

• B) P site

• C) E site

• D) B site

What is tRNA charging?

• A) A process to generate a supply of aminoacyl-tRNAs

• B) A process to generate a supply of ribosomes

• C) A process to generate a supply of mRNA

• D) A process to generate a supply of amino acids

What are ribosomes?

• A) Small protein particles

• B) Large protein particles

• C) Large ribonucleoprotein particles

• D) Small ribonucleoprotein particles

What component in the bacterial ribosome (as listed) has peptidyl transferase activity? (use the image below to help you identify the component)

• A. r-protein in the 50S ribosomal subunit

• B. r-protein in the 30S ribosomal subunit

• C. 23S rRNA

• D. 16S rRNA

What is the role of aminoacyl-tRNA synthetase?

• a) It catalyzes the reaction leading to an aminoacyl-tRNA and determines the specificity of this reaction.

• b) It binds with the tRNA and mRNA during translation.

• c) It breaks down aminoacyl-tRNA into amino acids and tRNA.

• d) It transfers ATP to tRNA.

How many aminoacyl-tRNA synthetases exist and what is their specificity?

• a) 2 synthetases, each for 10 amino acids.

• b) 20 synthetases, each for one amino acid.

• c) 10 synthetases, each for two amino acids.

• d) 15 synthetases, each for three amino acids.

What is the target for charging of tRNA?

• a) The first base at the 5’-end.

• b) The last base at the 3’-end.

• c) The middle base at the anticodon loop.

• d) The base at the D-loop.