exam 3 Flashcards
Transcription in eukaryotes requires 3 RNA polymerases, what are their names?
RNA poly I, II, and III
What does RNA poly I focus on?
large rRNA precursors
What does RNA poly II focus on?
Nearly all protein coding genes
What does RNA poly III focus on?
Smaller RNAs = tRNA, snRNA, and small rRNA recursors
In prokaryotes, how many RNA polymerases are there?
Only one
What does eukaryotic transcription require?
transcription factors
What do transcription factors do?
Bind specific promoters and bridge gap between RNA polymerase, thus activating or repressing transcription.
These bind upstream, within or downstream of a gene.
What are transcription factors in eukaryotes equal to in prokaryotes?
Sigma factors
Do prokaryotes contain transcription factors?
No, they are only found in eukaryotes, although prokaryotes contain sigma factors which is similar.
What initiates transcription for all genes – even without a TATA box?
TFIID
