lecture 2

Question 1

what inactivates gene transciption

Answer 1

chromatin condensation

Question 2

where does transcription occur in eukaryotes

Answer 2

DNA that is wrapped in chromatin

Question 3

chromatin needs to be ____ for a gene to be activated and ______ to happen

Answer 3

open
transcription

Question 4

chromatine mediated regulation is often called

Answer 4

epigenetic regulation of gene expression

Question 5

heterochromatin

Answer 5

-regions of chromosomes that are intensely stained
—DNA is more densely packed
-rich in repetitive DNA
—not accessible to transcriptional machinery
—inactive genes are found on heterochromatin

Question 6

euchromatin - eu = true

Answer 6

• lightly stained chromosome regions
  –active genes found in euchromatin
  –accessible to transcriptional machinery

Question 7

RNA polymerase 1

Answer 7

RNA transcribed - Pre-rRNA (28s, 18s,5.85s rRNAs)
RNA function - ribosome components, protein synthesis

Question 8

RN polymerase 2

Answer 8

RNA transcribed-
MRNA
snRNAs
siRNAs
miRNAs
RNA Functions-
encodes protein
RNA splicing
chromatin-mediated repression, translation control
translation control

Question 9

RNA Polymerase 3

Answer 9

RNA transcribed
tRNAs
5s rRNA
snRNA U6
75 RNA
other small RNAs
RNA functions
protein synthesis
ribosome components, protein synthesis
RNA splicing
signal recognition particle for the insertion of polypeptides into the endoplasmic reticulum
various functions, unknown for many

Question 10

RN pol 2 consists of ___ polypeptides

Answer 10

12
RPB1, RPB2…

Question 11

what part of teh polymerase accomidates DNA

Answer 11

Clamp Domain

Question 12

after positioning over DNA the clamp is closed by

Answer 12

a bridge

Question 13

the synthesis of RNA takes place in the _____ with the participation of ___

Answer 13

catalytic center
Mg++

Question 14

The synthesized RNA exits through a…

Answer 14

channel and is immediately capped by 7m guanosine

Question 15

eukaryotic RNA polymerase 2 contains a unique

Answer 15

Carboxy-terminal domain (CTD)

Question 16

CTD plays a key role in..

Answer 16

initiation
release
elongation
Processing of the synthesized mRNA

Question 17

the ___ residues in the CTD are _____ upon transition from ___ to ____

Answer 17

Ser
phosphorylated
initiation
elongation

Question 18

transcribed genes are regulated by

Answer 18

• core promoter regions
• promoter - proximal binding sites for transcriptional activators
• distal enhansors or repressors
• chromatin structure

Question 19

4 core promotor sequences

Answer 19

• TATA box
• initiator
• BRE (TFIIB recognition element)
• DPE (Downstream Promotor Element)

Question 20

general POL2 transcription factors (GTFs) assemble the preinitiation complex over the

Answer 20

core promotor sequence

Question 21

RNA Pol2 GTFs are

Answer 21

• TFII
• TFIIA
• TFIIB
• TFIID
• TFIIE
• TFIIH