Lecture 07

Question 1

What is used as the intermediary for protein synthesis?

Answer 1

RNA

Question 2

Transcription

Answer 2

DNA is copied to RNA

Question 3

Translation

Answer 3

RNA used as a template to direct protein synthesis

Question 4

mRNAs

Answer 4

Messenger RNAs - code for protein

Question 5

rRNAs

Answer 5

Ribosomal RNAs - form the basic structure of the ribosome and catalyze protein synthesis

Question 6

tRNAs

Answer 6

Transfer RNAs - central to protein synthesis as adaptors between mRNA and amino acids

Question 7

snRNAs

Answer 7

Small nuclear RNAs - function in a variety of nuclear processes including splicing of pre-mRNA

Question 8

snoRNAs

Answer 8

Small nucleolar RNAs - help to process and chemically modify rRNAs

Question 9

miRNAs

Answer 9

MicroRNAs - Regulate gene expression by blocking translation of specific mRNAs and cause their degradation

Question 10

siRNAs

Answer 10

Small interfering RNAs - turn off gene expression by directing degradation of selective mRNAs and establishment of compact chromatin structures

Question 11

What are the 3 components of mRNA processing in eukaryotes?

Answer 11

1. RNA capping
2. RNA splicing
3. Polyadenylation (polyA tail)

Question 12

What is used for the RNA cap during processing?

Answer 12

7-methyl guanosine

Question 13

What is removed during RNA splicing?

Answer 13

Introns

Question 14

RNA Pol

Answer 14

Bacterial RNA polymerase; Multi-subunit complex; catalyzes formation of phosphodiester bonds; proof-reading nuclease

Question 15

What are the 2 common promoter motifs in prokaryotic transcription?

Answer 15

• 35 sequence (TTGACA)

- 10 sequence (TATAAT)

Question 16

What eases superhelical tension during elongation in prokaryotes?

Answer 16

DNA gyrase

Question 17

What causes the dissociation of RNA Pol and RNA during prokaryotic termination?

Answer 17

Stable hairpin structure formed by palindromic GC, then AT rich regions

Question 18

How many RNA polymerases are used in eukaryotic transcription and which one is most predominant?

Answer 18

3 polymerases: RNA polymerase II is predominant

Question 19

What is unique about RNA Polymerase II?

Answer 19

CTD “tail”, regulation by phosphorylation on Ser residues of the CTD

Question 20

What are the functions of TFIIs?

Answer 20

1. Position RNA polymerase at promoter,
2. Pulling apart 2 strands of DNA so transcription begins
3. Release RNA polymerase from promoter for elongation

Question 21

What is the predominant promoter sequence in eukaryotic transcription?

Answer 21

TATA box

Question 22

TFIID

Answer 22

Recognizes TATA box

Question 23

TFIIB

Answer 23

Recognizes BRE in promoters and accurately positions RNA polymerase at start site of transcription

Question 24

TFIIF

Answer 24

Stabilizes RNA polymerase interaction with TBP and TFIIB; helps attract TFIIE, TFIIH

Question 25

TFIIE

Answer 25

Attracts, regulates TFIIH

Question 26

TFIIH

Answer 26

Unwinds DNA at transcription start point, phosphorylates Ser5 of CTD - releases RNA polymerase from promoter

Question 27

What relieves superhelical tension during eukaryotic elongation?

Answer 27

DNA topoisermase

Question 28

Transcriptional activator of initiation in vivo

Answer 28

Attracts RNA Pol II to transcription initiation start site

Question 29

Mediator of initiation in vivo

Answer 29

Allows activator proteins to communicate with RNA Pol II and general transcription factors

Question 30

What proteins are important in polyadenylation of mRNA?

Answer 30

Cleavage and Poly adenylation Specificity Factor (CPSF) and Cleave Stimulation Factor (CstF)