Ch. 17b Eukaryotic Transcription (Exam 2) Flashcards
What’s the difference between prokaryotic transcription and eukaryotic transcription in terms of where they take place?
Prokaryotic = DNA template
Eukaryotic = chromatin template
Define transcription factor.
Any protein needed to start transcription but is not part of the RNA polymerase
Aside from chromatin being opened and not condensed, what must happen to the nucleosome octamers before transcription can occur?
They must be moved or removed from promoter sequences
What is the difference between prokaryotic and eukaryotic transcription in terms of how their RNA polymerase activity?
Prokaryotic = RNA polymerase can read DNA
Eukaryotic = RNA polymerase canNOT read DNA
What are cis-acting elements?
Non-coding regions that regulate transcription of nearby genes
What are basal transcription factors?
Transcription proteins that bind to certain sites, like the promoter, to activate transcription
Define core promoter.
Region containing all binding sites necessary for RNA polymerase to bind and function
Does RNA polymerase extend to the upstream region of the promoter?
No, but it does bind to the start point of transcription, which is a little bit downstream of the promoter
What are the 3 RNA polymerase classes?
I, II, III
In RNA polymerase II, you will find these types of RNA…
mRNA & some small RNAs
Are transcription factors or RNA polymerases responsible for recognizing the promoters in eukaryotes?
Transcription factors
How do basal transcription factors help RNA polymerase?
Basal transcription factors create a 3D structure to provide a target for the RNA polymerase i.e. they act as a liaison from promoter to RNA polymerase
What is an enhancer?
Non-coding sequence that enhances the transcription process and the likelihood that a gene will be transcribed
What are housekeeping genes (constitutive promoters)?
Promoters constitutively expressed and needed in all cells
In terms of their amount of subunits, what do RNA polymerases I-III have in common?
They all have about 12 subunits
RNA polymerase I synthesizes rRNA in the…
Nucleolus
RNA polymerase II synthesizes mRNA in the…
Nucleoplasm