Nucleic Acids - Mock Test 50

Question 491

The binding of prokaryotic DNA dependent RNA polymerase to promoter sites of genes is inhibited by the antibiotic?

A) Puromycin B) Rifamycin C) Terramycin D) Streptomycin

---

No Details

Question 492

Erythromycin acts on ribosomes and inhibit?

A) Formation of initiation complex B) Binding of aminoacyl tRNA C) Peptidyl transferase activity D) Translocation

---

No Details

Question 493

Streptomycin prevents synthesis of polypeptide by?

A) Inhibiting initiation process B) Releasing premature polypeptide C) Inhibiting peptidyl transferase activity D) Inhibiting translocation

---

No Details

Question 494

In prokaryotes, chloramphenicol?

A) Causes premature release of the polypeptide chain B) Causes misreading of the mRNA C) Depolymerises DNA D) Inhibits peptidyl transferase activity

---

No Details

Question 495

Tetracylin prevents synthesis of polypeptide by?

A) Blocking mRNA formation from DNA B) Releasing peptides from mRNA-tRNA complex C) Competing with mRNA for ribosomal binding sites D) Preventing binding of aminoacyl tRNA

---

No Details

Question 496

The mushroom poison amanitin is an inhibitor of?

A) Protein synthesis B) mRNA synthesis C) DNA synthesis D) Adenosine synthesis

---

No Details

Question 497

In eukaryotic cells?

A) Formylated tRNA is important for initiation of translation B) Cyclohexamide blocks elongation during translation C) Cytosolic ribosomes are smaller than those found in prokaryotes D) Erythromycin inhibits elongation during translation

---

No Details

Question 498

Translocation of the newly formed peptidyl tRNA at the A site into the empty P site involves?

A) EF-II, GTP B) EF-I, GTP C) EF-I, GDP D) Peptidyl transferase, GTP

---

No Details

Question 499

The α-amino group of the new amino acyl tRNA in the A site carries out a nucleophilic attack on the esterified carboxyl group of the peptidyl tRNA occupying the P site. This reaction is catalysed by?

A) DNA polymerase B) RNA polymerase C) Peptidyl transferase D) DNA ligase

---

No Details

Question 500

The newly entering amino acyl tRNA into A site requires?

A) EF-II B) Ribosomal RNA C) mRNA D) EF-I

---

No Details