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Flashcards in Transcription Deck (22)
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1

Groups of genes expressed together in prokaryotes

Operons

2

How many RNA polymerases do prokaryotes have?

1

3

Name and type RNA pol in eukaryotes

Pol I: rRNA
Pol II: mRNA
Pol III: tRNA

4

How are the RNA pol in eukaryotes specific to the type of RNA they produce?

Recognize different promoter sequences

5

This protein binds to bacterial promoters to direct RNA Pol to the correct region

Sigma factor

6

T/F Transcription can occur on opposite DNA strands simultaneously

T

7

Two physical factors that terminate prokaryotic RNA Pol

1. Hairpin loop
2. Rho factor binding

8

Term for DNA sequence that encodes one polypeptide

Cistron

9

How many introns does the typical prokaryotic cistron contain?

0

10

Describe bacterial RNA transcription

1. Sigma factor binds RNA promoter region
2. RNA Pol binds DNA strand and begins transcription
3. Sigma factor falls off
4. RNA Pol transcription continues
5. Transcription is terminated at hairpin or Rho factor

11

Three basic steps of eukaryotic RNA processing

1. 5' cap
2. 3' poly-A tail
3. Intron removal

12

T/F Intron removal occurs in the cytosol

F (it occurs in the nucleus)

13

These transcription factors are required for all eukaryotic RNA Pol transcriptions

General transcription factors

14

Steps of eukaryotic RNA Pol II initiation

1. TFI proteins (general transcription factors) bind promotor region
2. RNA Pol and other general transcription factors bind
3. Helicase + phosphorylation activation
4. General transcription factors removed
5. Off it goes

15

T/F Enhancers are DNA sequences that bind activator proteins that are always close to the site of transcription

F

16

These proteins help RNA Pol II move along DNA sequences

Elongation factors

17

T/F 5' capping begins DURING transcription

T

18

Structure that helps ensure accurate splicing

Spliceosome

19

Two separate two-nucleotide sequences that are invariant in coding the beginning and end of introns

GU (begin)
AG (end)

20

Describe the steps in mRNA splicing

1. Nucleophilic intronic adenine attacks 5' end of intron
2. The now freed --OH on exon attacks other exon
3. Lariat loop is released and exons are joined

21

How can our genome have ~30,000 start codons but we produce far more proteins?

Alternative splicing

22

MicroRNAs are transcribed using which RNA Pol

II