Flashcards in Transcription Deck (16):
Transcription in prok
DNA -> mRNA
-takes place in the cytoplasm
Transcription in euk
-takes place in the nucleus
What is a gene
DNA sequence that codes for a protein
What do we want to transcribe in transcription?
How many strands do we copy into RNA?
-only one strand
---the "template strand" or "anti-sense"
-in replication you copy both strands
What is the difference between the comlementary DNA strand and the new RNA strand?
-Uracil instead of thymine
-attracts RNA pol to come and bind to the gene
Where tracription begins
-the beginning of the gene after the promoter
What pulls the strands apart
What do you do once you make the strand of RNA?
-depends if you are a prok or euk
-prok: coupled to translation because both take place in the cytoplasm
-mRNA is the only one that codes for proteins
-tRNA and rRNA are involved in translation of the mRNA
-in prok all three are made by the same pol
-in euk there are three dif pol that make them separate
RNA POL I
RNA POL II
RNA POL III
I- makes rRNA
II- makes mRNA
Promoters in prok vs euk
-prok: there is a "-35" element and a
"-10" element called the pribnow box rich in A and T
-euk: tata box at "-25" rich in A and T
-Only in euk
-exons code for part of the protein
-introns need to be cut out and the exons are spliced together
-you attach a 5' cap at one end of splicing and a polyAtail
-it is then shipped out of the nucleus and makes it to the ribosomemfor translation
Where does transcription begin?
-begins at the start site
-binding begins at the promoter region
Replication starts at the origin of replication