QUESTION 1 Phosphorylation of elongation factors 2 EF2 and 2

QUESTION 1 Phosphorylation of elongation factors 2 (EF2) and 2B (EF2B):

a. blocks their exchange of bound GDP for GTP

b. allows them to be recycled back to the ribosome

c. blocks the addition of a terminal phosphate to the bound GDP

d. allows them to initiate translation 1 points Saved

QUESTION 2 The 7-methyl guanosine cap and the poly-A tail of a mRNA are both involved in or required for?

a. protecting an mRNA from exonuclease attack

b. protecting an mRNA from endonuclease attack

c. miRNA activity d. alternative splicing

QUESTION 3 Small nucleotide sequences such as siRNA or miRNA are involved in BOTH post-transcriptional and translational regulation of gene expression. True False

QUESTION 4 Phosphorylation of eIF4E:

a. inhibits translation

b. enhances translation

c. activates iron response elements d. has no effect on translation

QUESTION 5 A process called alternative splicing of mRNA transcripts can produce mRNAs with ________ from the same gene. a. one different exon

b. more or fewer exons

c. completely different exons

d. all of the above

QUESTION 6 Phosphorylation of eIF2:

a. has no effect on translation

b. enhances translation

c. inhibits translation

d. prolongs elongation

QUESTION 7 The half-life of an mRNA molecule is primarily or predominantly dependent on which of the following transcript structures?

a. poly-A tail

b. the coding region

c. the 5\'-cap

d. 5\'-UTR

QUESTION 8 To function as a repressor-binding site, the iron response element (IRE) must be in the 5-UTR region of the ferritin mRNA. This suggests that regulatory protein binding to this IRE does what?

a. inhibits the translocation step of translation

b. blocks the translation start site

c. regulates mRNA degradation

d. promotes circularization of the mRNA template

QUESTION 9 Messenger RNAs have varying half-lives in the cytoplasm, and those differences are usually due to differences in the sequences near the 5\'-end of the mRNA. True False

QUESTION 10 The presence of an Iron Response Element affects translation of every mRNA transcript. True False

Solution

1. phosphorylation will inhibit the elongation factor that blocks their exchange of bound GDP for GTP.

2. 7-methyl guanosine cap and the poly-A tail of a mRNA are added at the end of mRNA to protect from exonuclease attack.

3. true. siRNA or miRNA are involved in post-transcriptional and translational regulation of gene expression.

4.Phosphorylation of eIF4E: enhances translation