Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

1
...
Transcription factors bind to the promoter (sequence of DNA where RNA
pol attaches, probably includes TATAAAA box and is about 25 nucleotides
upstream from AUG)
3
...
RNA Pol transcribes the Transcription Unit at rate of 40 nucleotides per
second, exposing 10-20 at a time
5
...
10-35 nucleotides later, proteins cut the strand free but Pol II keeps
transcribing while the strand is being degraded from 5’ end by enzymes
7
...
5’ end of Primary Transcript receives 5’ cap; a modified form of Guanine (G)
2
...
RNA Splicing begins with a protein/RNA complex called the Spliceosome
4
...
Snurps (snRPS) hold the extrons and introns for spliceosome
6
...
mRNA is ready to leave the nucleus and go to the cytosol for translation

Initiation










DNA unwinds
RNA pol begins RNA synthesis at the start point
RNA Polymerase DOES NOT NEED A PRIMER
Sequence of DNA where RNA Pol attaches and initiates transcription is known as the promoter
In BACTERIA, the sequences that signals the end of transcription is the TERMINATOR
Promoter determines which strand is used as the template
Crucial promoter = TATA Box (25 nucleotides upstream from starting point)
Promoters usually extend several dozen nucleotides upstream from the starting point
RNA Pol binds in a precise LOCATION & ORIENTATION on the promoter

 “Downstream” = direction of transcription; “upstream” is the other way
 Transcription Unit = the stretch of DNA downstream from the promoter that is transcribed into
an RNA molecule
 Bacteria have 1 type of RNA Pol; Eukaryotes have 3+, one for pre-mRNA is called Pol II

---