#Question id: 4289
#Unit 3. Fundamental Processes
Match the Following
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A. fidelity of codon recognition |
1. involves two adjacent adenine residues in the 16S rRNA component located within the A-site of the small subunit. These bases form hydrogen bonds with the minor groove of each correct base pair formed between the anticodon and the first two bases of the codon in the A-site |
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B. kinetic selectivity |
2. Even a single mismatch in the codon–anticodon base pairing alters the position of EF-Tu, reducing its ability to interact with the factor-binding center. This, in turn, leads to a dramatic reduction in EF-Tu GTPase activity |
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C. Accommodation |
3. When the charged tRNA is first introduced into the A-site in a complex with EF-Tu-GTP, its 30 end is distant from the site of peptide-bond formation. To participate successfully in the peptidyl transferase reaction, the tRNA must rotate into the peptidyl transferase center of the large subunit in a process |
#Question id: 4290
#Unit 3. Fundamental Processes
23S rRNA catalyze peptide-bond formation explained by the model of proton shuttle given in figure.
Which of the following statements is/are CORRECT for this model?
A. Base pairing between the 23S rRNA and the CCA ends of the tRNAs in the A- and P-sites positions is crucial for this reaction
B. This catalytic mechanism involves entropy
C. 2’-OH of the P-site tRNA act as part of a “proton shuttle”
D. it is a protein that catalyses peptide bond formation
#Question id: 4291
#Unit 3. Fundamental Processes
There are two classes of release factors. Match the following
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A. Class I release factors |
1. recognize the stop codons and trigger hydrolysis of the peptide chain from the tRNA in the P-site. |
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B. Class II release factors |
2. stimulate the dissociation of the class I factors from the ribosome after release of the polypeptide chain. |
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C. RF1 |
3. recognizes the stop codon UAG |
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D. RF2 |
4. recognizes the stop codon UGA. |
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E. RF1 & RF2 |
5. UAA |
#Question id: 4292
#Unit 3. Fundamental Processes
Termination of prokaryotic translation take place in three set of events. Match the following
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A. glycine glycine glutamine, GGQ and RF3-GTP |
1. That is essential for polypeptide release in first step, release of class I RF |
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B. RRF & EF-G |
2. the tRNAs and the mRNA must be removed from the ribosome, and the ribosome must dissociate into its large and small subunits. |
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C. IF3 |
3. Release of ribosome |
#Question id: 4293
#Unit 3. Fundamental Processes
Match antibiotics with their effects
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A. Tetracycline |
1. Inhibits aminoacyl-tRNA binding to A-site in prokaryotes |
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B. Chloramphenicol |
2. Blocks correct positioning of A-site aminoacyl-tRNA for peptidyl transfer reaction in prokaryotes |
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C. Fusidic acid |
3. Prevents release of EF-G–GDP from the ribosome in prokaryotes |
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D. Ricin |
4. Prevents activation of translation factor GTPases in both Prokaryotes and Eukaryotes |
#Question id: 4294
#Unit 3. Fundamental Processes
Not surprisingly, in several instances, the two binding sites for the regulatory ribosomal protein are related to each another. In the case of the S8 ribosomal protein, the two binding sites share substantial similarities. The sequence of the binding site in the mRNA reveals a clear mechanism by which S8 inhibits translation. Which of the following are INCORRECT regarding this mechanism?
A. Free rRNA content in cytoplasm activates ribosomal protein biogenesis
B. RNA-binding proteins regulate their expression by binding to their own mRNAs, including some aminoacyl-tRNA synthetases
C. In case of “NO FREE rRNA” ribosomal protein transcript is efficiently translated by autoregulation process
D. In case of “NO FREE rRNA” ribosomal protein transcript undergoes to autorepression