Question : Which step of translation requires mRNA decoding by a protein : 2134184
21) Which step of translation requires mRNA decoding by a protein?
D. A and C
22) The signal recognition particle (SRP) is a ribonucleoprotein complex that binds to ribosomes translating polypeptides that bear a signal sequence for targeting to
A. the endoplasmic reticulum.
B. the nucleus.
C. the mitochondria.
D. the cytoplasm.
23) What is a molecular chaperone?
A. A protein that binds to ribosomes at the rough ER membrane.
B. A protein that post-translationally modifies a nascent polypeptide by adding or removing a phosphate group.
C. A protein component of the large ribosomal subunit that helps with correct peptide bond formation.
D. A protein that helps a nascent polypeptide chain to adopt its correct three-dimensional fold.
24) When the translation initiation factor eIF2 is phosphorylated in response to a sudden temperature increase or viral infection, translation can be greatly inhibited. In this case, phosphorylated eIF2 is under _______________ control, and the phosphorylation of eIF2 leads to global (general or widespread) _____________ control.
A. translational; post-translational
B. post-translational; translational
C. post-translational; transcriptional
D. translational; transcriptional
25) In response to unfavorable conditions such as hypoxia or osmotic shock, translation can be globally repressed by
A. modification of mRNA 7-methylguanosine caps
B. ribosome stalling via a conformation change in eEF2
C. phosphorylation of eIF2a
D. puromycin synthesis