Molecular Biology - Das - Chapter 18 [Lecture_ Translation II] Flashcards _ Quizlet

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12/20/23, 1:24 AM Molecular Biology - Das - Chapter 18 [Lecture: Translation II] Flashcards | Quizlet https://quizlet.com/333001479/molecular-biology-das-chapter-18-lecture-translation-ii-flash-cards/ 1/7 Molecular Biology - Das - Chapter 18 [Lecture: Translation II] 7 studiers in 3 days Leave the first rating Students also viewed Terms in this set (27) Try Magic Notes and save time Upload notes Bio 99 Final Exam Review 10 terms daniel_lomboy7 Preview HW 9 6 terms ngriswel Preview The Genetic Code and Translation R ... 29 terms mikaela_b3 Preview Molecular B 19 terms kgoldsb The bacterial Shine-Dalgarno mRNA sequence is: A. a translation termination signal. B. the ribosomal binding site. C. a translational elongation factor. D. a protein coding region. B. the ribosomal binding site. The bacterial Shine-Dalgarno mRNA sequence is specifically recognized by: A. protein S5 of the 30S subunit. B. N-formylmethionyl-tRNAfMet. C. the 23S rRNA of the 50S subunit. D. the 16S rRNA of the 30S subunit. D. the 16S rRNA of the 30S subunit. Which of the following describes an accurate order of events in translation? A. Ribosomal translocation occurs before the first aminoacyl-tRNA molecule binds to the small subunit. B. Initiation of translation occurs only after the small subunit dissociates from the mRNA. C. The large subunit of the ribosome binds the mRNA before the small subunit. D. The first aminoacyl-tRNA molecule binds to the small subunit before the large subunit binds. D. The first aminoacyl-tRNA molecule binds to the small subunit before the large subunit binds.

12/20/23, 1:24 AM Molecular Biology - Das - Chapter 18 [Lecture: Translation II] Flashcards | Quizlet https://quizlet.com/333001479/molecular-biology-das-chapter-18-lecture-translation-ii-flash-cards/ 2/7 Which of the following is NOT true of the eukaryotic internal ribosome entry site (IRES)? A. It is important for efficient translation of mRNA molecules lacking a 5' cap. B. The eIF4F factor binds to this site. C. They are never found in mRNA molecules containing a 5' cap. D. It positions the mRNA start codon correctly on the 40S subunit. C. They are never found in mRNA molecules containing a 5' cap. Which of the following is NOT true of the formation of a eukaryotic translation initiation complex? A. eIF4F binds to the 5' cap of the mRNA. B. eIF2 binds to the A site to block the binding of the initiating tRNA. C. At least two GTP molecules are hydrolyzed per initiation event. D. eIF1, eIF1A, eIF2, and eIF3 are displaced before the 60S subunit joins the 40S subunit. B. eIF2 binds to the A site to block the binding of the initiating tRNA. Which site on the ribosome is never occupied by a tRNA linked to a nascent polypeptide chain? A. the A site B. the P site C. the E site C. the E site Which of the following is not true of the formation of a bacterial translation initiation complex? A. The 30S ribosome associates with the mRNA before the 50S ribosome. B. N-formylmethionyl-tRNAfMet binds in the P site. C. IF-3 binding to GTP is required for the charged tRNA to associate with the first mRNA codon. D. IF-1, IF-2, and IF-3 dissociate upon the 50S subunit binding. C. IF-3 binding to GTP is required for the charged tRNA to associate with the first mRNA codon. Which of the following is NOT an essential component of the bacterial initiation stage of translation? A. mRNA B. IF-2 C. ATP D. N-formylmethionyl-tRNAfMet C. ATP Learn

12/20/23, 1:24 AM Molecular Biology - Das - Chapter 18 [Lecture: Translation II] Flashcards | Quizlet https://quizlet.com/333001479/molecular-biology-das-chapter-18-lecture-translation-ii-flash-cards/ 3/7 Which of the following best describes the composition of the bacterial translation initiation complex? A. 30S and 50S subunits, mRNA start codon paired with the anticodon of fMet-tRNAfMet, fMet- tRNAfMet bound in the P site, A site is open, GTP is bound by IF-2 B. 30S and 50S subunits, mRNA start codon paired with the anticodon of fMet-tRNAfMet, fMet- tRNAfMet bound in the P site, A site is open C. 30S and 50S subunits, mRNA start codon paired with the anticodon of fMet-tRNAfMet, fMet- tRNAfMet bound in the A site, P site is open D. 30S and 50S subunits, mRNA start codon paired with the anticodon of fMet-tRNAfMet, fMet- tRNAfMet bound in the A site, P site is open, GTP is bound by IF-2 B. 30S and 50S subunits, mRNA start codon paired with the anticodon of fMet- tRNAfMet, fMet-tRNAfMet bound in the P site, A site is open The function of bacterial eEF1 is to: A. convert eEF1A-GDP to an active form. B. allow binding of aminoacyl-tRNAs to the A site of the ribosome. C. convert GTP to GDP. D. move the peptidyl-tRNA from the A site to the P site. E. deacylate tRNAs. A. convert eEF1A-GDP to an active form. Which of the following is NOT an essential component of the bacterial elongation stage of translation? A. functional 70S ribosome B. EF-Ts C. aminoacyl-tRNAs D. ATP D. ATP Which of the following is not an essential component of the bacterial termination and release stage of translation? A. IF-3 B. GTP C. stop codon in mRNA D. RF-1 B. GTP Learn

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12/20/23, 1:24 AM Molecular Biology - Das - Chapter 18 [Lecture: Translation II] Flashcards | Quizlet https://quizlet.com/333001479/molecular-biology-das-chapter-18-lecture-translation-ii-flash-cards/ 4/7 Which of the following is true of bacterial translation termination? A. The ribosome continues to synthesize protein until it reaches the 3' end of the mRNA. B. Termination requires the degradation of the ribosome. C. Termination is signaled by the presence of a stop codon in the mRNA. C. Termination is signaled by the presence of a stop codon in the mRNA. Which of the following is NOT a function of the release factors of bacterial translation termination? A. mediating the hydrolysis of the terminal peptidyl- tRNA bond B. assisting in the initial folding of the nascent polypeptide chain C. releasing the last uncharged tRNA from the P site D. recognition of a stop codon B. assisting in the initial folding of the nascent polypeptide chain Which of the following is NOT a function of EF-G in bacterial translation? A. the hydrolysis of GTP B. the mediation of elongation C. the separation of the ribosome from the mRNA at termination D. the hydrolysis of the terminal peptidyl-tRNA bond D. the hydrolysis of the terminal peptidyl-tRNA bond Which one of the following bacterial translational proteins is NOT a GTP-binding protein? A. IF-2 B. EF-Tu C. EF-G D. RF-1 D. RF-1 Eukaryotic proteins do not require a targeting signal if they are destined to function in the: A. nucleus. B. lysosome. C. plasma membrane. D. cytoplasm. D. cytoplasm. Learn

12/20/23, 1:24 AM Molecular Biology - Das - Chapter 18 [Lecture: Translation II] Flashcards | Quizlet https://quizlet.com/333001479/molecular-biology-das-chapter-18-lecture-translation-ii-flash-cards/ 5/7 Which of the following is NOT an essential component of the eukaryotic initiation stage of translation? A. 40S ribosome B. eIF2 C. GTP D. N-formylmethionyl-tRNAfMet D. N-formylmethionyl-tRNAfMet Which of the following statements explains how N- formylmethionine (fMet) is incorporated only in response to the 5'-AUG initiation codon in E. coli, given that methionine has only one codon? A. There is only one tRNA with the CAU anticodon. B. Only Met-tRNAmet can bind to a specific ribosomal entry site. C. The N-formyl group on methionine prevents fMet from entering interior positions in a polypeptide. D. fMet is always incorporated at interior AUG sites and then deformylated after translation. C. The N-formyl group on methionine prevents fMet from entering interior positions in a polypeptide. Which of the following statements is not true of the formation of N-formylmethionyl-tRNAfMet? A. It is formed in two successive reactions. B. A formyl group is transferred to methionine before it is added to tRNAfMet. C. The transformylase enzyme most likely recognizes a unique structural feature of tRNAfMet. D. The tRNAfMet is charged by the Met-tRNA synthetase. B. A formyl group is transferred to methionine before it is added to tRNAfMet. Which of the following statements about translation is NOT true? A. Protein synthesis begins with the N-terminal end. B. The AUG initiation codon specifies an N-terminal methionine residue. C. The three steps of elongation are repeated for each codon of the mRNA. D. The ribosome is degraded after dissociating from the stop codon. D. The ribosome is degraded after dissociating from the stop codon. Learn

12/20/23, 1:24 AM Molecular Biology - Das - Chapter 18 [Lecture: Translation II] Flashcards | Quizlet https://quizlet.com/333001479/molecular-biology-das-chapter-18-lecture-translation-ii-flash-cards/ 6/7 Which of the following is true of the trafficking of proteins from the cytosol to the endoplasmic reticulum? A. The proteins are first completely synthesized in the cytosol. B. The signal recognition particle (SRP) does not enter the ER lumen. C. The polypeptide signal sequence is cleaved by the peptide translocation complex. D. The SRP receptor faces the ER lumen side of the ER membrane. B. The signal recognition particle (SRP) does not enter the ER lumen. Which of the following is not true of the translocation step of translational elongation in bacteria? A. The deacylated tRNA is moved from the P site to the E site. B. EF-G binds to the A site, mimicking a EF-Tu- aminoacyl-tRNA complex. C. EF-G hydrolyzes GTP. D. The peptidyl-tRNA moves from the P site to the A site. D. The peptidyl-tRNA moves from the P site to the A site. Which of these stages of translation is most important to the fidelity of protein synthesis? A. formation of aminoacyl-tRNAs B. initiation of translation at an AUG codon C. translocation of the peptidyl-tRNA from the A site to the P site during elongation D. termination of translation at a STOP codon A. formation of aminoacyl-tRNAs Which of the following best explains why not all individual aminoacyl-tRNA synthetase enzymes recognize the correct tRNA molecules through the anticodon sequence? A. All tRNA molecules have the same anticodon sequence. B. Synthetases only contact the tRNA molecules at the 3'-terminal hydroxyl. C. More than one codon may code for one amino acid. D. There are 61 different aminoacyl-tRNA synthetase enzymes. C. More than one codon may code for one amino acid. Learn

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12/20/23, 1:24 AM Molecular Biology - Das - Chapter 18 [Lecture: Translation II] Flashcards | Quizlet https://quizlet.com/333001479/molecular-biology-das-chapter-18-lecture-translation-ii-flash-cards/ 7/7 Kinetic proofreading allows an enzyme to discriminate between two substrates by: A. using a binding pocket of a specific size. B. using a multistep reaction and energy to reverse reactions. C. using a binding pocket of a specific shape. D. increasing the rate of the single chemical step of the reaction. B. using a multistep reaction and energy to reverse reactions. Different aminoacyl-tRNA synthetases: A. may bind the same amino acid. B. may bind the same tRNA. C. do not appear to recognize the same features of tRNAs. D. will always recognize both the acceptor stem and anticodon sequences of tRNAs. E. will always recognize the complete tRNA anticodon sequence. C. do not appear to recognize the same features of tRNAs. Learn

Molecular Biology - Das - Chapter 18 [Lecture_ Translation II] Flashcards _ Quizlet

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