Transcription Flashcards Preview

Biochem > Transcription > Flashcards

Flashcards in Transcription Deck (86)
Loading flashcards...
1

What is transcription?

Synthesis of RNA from DNA

2

What stores the genetic information?

Coding (sense) strand

3

What is a Antisense strand?

Non Coding (antisense) strand - template

4

RNA is synthesised from?

the Antisense strand

5

Is primer needed in transcription?

no

6

What is the functional unit of DNA?

The transcription unit (TU)

7

What regions does the Transcription Unit (TU) compose of?

- (1) promoter: regulatory function
- (2) RNA coding region

8

Where is the Transcription start site?

Located between promoter and RNA coding region -> transcription starts form this point

9

What is the "Upstream" direction?

= from the start site towards promoter ("left"), bases found here get numbers minus 1,2 etc. when moving away from the start site.

10

What is the "Downstream" direction?

= from the start site towards RNA coding region ("right"), bases found here get numbers flus 1, 2 etc. whn moving away from start site.

11

What main things does the transcritpion unit compose of?

- Transcription start site
- upstream
- downstream

12

What is responsible for the regulation of transcription?

the Promoter

13

What are the most important consensus sequences of promoter regions?

- TATA-box
- GC-box
- CAP - cAMP binding site

14

What is TATA-box?

It is an important consensys sequence of the promoter region.

- Called Pribnow-box in Prokaryotes
- Rich in T and A bases
- RNA polymerase binds tightly to this box

15

What is GC-box?

It is an important consensys sequence of the promoter region.

- Rich in G and C bases
- RNA polymerase binds loosely to this box

16

What is CAP-cAMP binding site?

It is an important consensys sequence of the promoter region.

- Only in prokaryotes
- Binding of CAP-cAMP-complex -> one of the prerequisites of transcritpion

17

Such DNa sequence which is coding one functional unit?

Gene,/structure gene

18

What is polycistronic transcription unit?

One transcription is composed of several genes (only in prkaryotes)

19

What is monocistrnic transcription unit?

One transcription unit is composed of one gene (only in eukaryotes)

20

What can be found inside the genes of Eukaryotes?

Introns and exons

21

What is Introns?

can be found in pre-mRNA (primary transcript) only -> they are cut out -> Mature mRNA contains no intron

22

What are Exons?

mature mRNA contains exons only

23

What is the termination signal?

transcription finishes here

24

What is translation?

mRNA transports genetc information from DNA to the protein synthesis

25

What are the phases of transcription of mRNA of prokaryotes?

- Initiation
- Elongation
- Termination

26

What is the function of the RNA polymerase in Prokaryotes?

Catalyses transcription of all types of RNA

27

RNA polymerase + sigma factor =

RNA polymerase holoenzyme -> specific affinity of the enzyme to the promoter -> holoenzyme binds tightly to TATA (pribnow) and loosely to GC-box of promoter

28

What is RNA polymerase holoenzyme?

specific affinity of the enzyme to the promoter -> holoenzyme binds tightly to TATA (pribnow) and loosely to GC-box of promoter

29

What is necessary for the initiation of transcription in Prokaryotes?

Binding of CAP- cAMP complex to the binding site on the promoter

30

Elongation of transcription of Prokaryotes happens when?

Signa factor is released from RNA polymerase