Final old test Part 2

Question 1

1. Transcriptional _______________ bind the regulatory DNA sequences and stimulate transcription. These… such as mediators.

Answer 1

Activators

Question 2

2. The DNA sequence to which RNA polymerase bind to initiate transcription of a gene is called _____________

Answer 2

Promoter

Question 3

3. The role of the sigma factor in prokaryotes transcription is to __________ to bind to different transcription sites under different conditions

Answer 3

Direct RNA polymerase

Question 4

4. RNA synthesis continues until the polymerase encounters a stop signal. The most common stop signal in prokaryotes is __________________ followed by snoRNA residues

Answer 4

Inverted repeats of GC-rich sequence

Question 5

Eukaryote RNA polymerase II genes code for __________-

Answer 5

mRNAs

Question 6

6. Processing of pre-tRNAs to produce tRNAs involve: ____________________

Answer 6

Cleavage of the pre-tRNAs by the enzyme known as RNaseP

Addition of CCA termination the 3’ end

Modification of bases at specific positions

Question 7

Processing of RNA transcripts occur with ___________, rRNA and mRNA

Answer 7

tRNA

Question 8

Splicing of the pre-mRNAs takes place in large complexes, called splicesomes, which have five types of _____________

Answer 8

Small nuclear RNAs (snRNA)

Question 9

Which of the following is not an example of a transcription factor DNA binding domain?

Answer 9

Acidic bases

Question 10

10. In eukaryotes premRNA are extensively modified before export into the nucleus. The 5’ end of the transcript is modified by____________________

Answer 10

methylguanesine cap

Question 11

11. Promoter contain several different sequence elements surround their transcript sites. The ____________

Answer 11

TATA box

Question 12

Eukaryotic gene repressor proteins are thought to act by _______________

Answer 12

Prevent binding of activator to the DNA

Interactions/ medical inhibiting factors. Inhibiting transcription

Question 13

aminoacyl RNA synthesase are enzymes that ____________

Answer 13

Attach amino acids

Question 14

14. Ribosomes are named according to their sedimentation rate in ultra-centrifuging. The combined size of prokaryote and eukaryote ribosomes are

Answer 14

70 and 80s

Question 15

During transcription the codons on the mRNA are recognized by complementary base paring to the anticodon on the ___________.

Answer 15

tRNA

Question 16

Translation occurs in three stages which on is not one of these stages?

Answer 16

Epigenetic modification

Question 17

The ribosome had three binding sites, which one is incorrect?

Answer 17

TC terminations

Question 18

The elongation factor that brings the tRNA to the aminoacyl tRNA to the eukaryotic ribosomes , then the release of GTP base paring is ____________

Answer 18

EFF-1 alpha

Question 19

In eukaryotes translation always starts with ________

Answer 19

EIF5

Question 20

Elongation continues until a stop codon is translocated into the A site. _______ recognize the signals and terminate protein synthesis

Answer 20

Release factors

Question 21

The amount of protein in a cell is regulated by the _____________

Answer 21

Transcription agents

Translation of its mRNA

Degradation of the protein

Question 22

Which one is correct about small interfering RNAs (siRNAS)?

Answer 22

Produced by double stranded RNAs by the nuclease dicer

Generally pair with their targets and induce cleavage of mRNA

One stranded siRNAs –>complex (RISC)

Question 23

Phosphorylation of eukaryotes initiates factors 2(ELF2) and 2B (ELF2B) by regulatory protein kinase.

Answer 23

Blocks their exchange of bound GDP for GTP inhibiting initiation of transcription

Question 24

A signal peptase removes __________- from a polypeptide chain after it process through the channel into the rough ER

Answer 24

Removes a signal sequence

Question 25

Cells can regulate the amount and activities of their proteins by the following mechanism :

Answer 25

Regulation of small molecules

Phosphorylation

Protein-protein interaction

Question 26

Proteins are often regulated by phosphorylation of enzymes called ________

Answer 26

Protein kinases

Question 27

A major protein degradation pathway, a short polypeptide called ________ attaches to a protein to target it for degradation

Answer 27

Ubiquinone

Question 28

The signals that identify identify initiation codon are different in prokaryote than
eukaryotic cells. In Prokaryotes mRNA are preceded by ____________

Answer 28

Shine Dalagarno sequence

Question 29

??????????CAMP activates CAMP dependent proteins kinase by?

Answer 29

??????Binding requitioy subunits and reducing merine release from catouric subunits

Question 30

The eukaryotic 45S proteins transcript codes for _________ rRNAs

Answer 30

28S, 18S, and 5.8S

Question 31

In cotranslation translocation signal sequences are recognized and bound by ___________

Answer 31

Signal recognition particle

Question 32

???????32. The sequence Lus-Asp-Glu-Leu (KDEL) serves on an ER retention by binding KDEL ________ two proteins from the Golgi apparatus back to the ER

Answer 32

??????????????

Question 33

Protein folding in the ER is assisted by ___________

Answer 33

Bip

Question 34

Which of the following classes of lipids is synthesized in the Gogli?

Answer 34

Glycolipids

Question 35

?????Many proteins insert directly into the ER membrane through _______, recognized by SR1 not degraded by signal peptase.

Answer 35

??????

Question 36

New phospholipids are added only to cytosolic half of ER…. Passage of polar head through membrane, facilitated by ____________

Answer 36

Flippase