9: Prokaryotic DNA Transcription Flashcards
What kind of experiment shows where RNA or other proteins move in a cell?
A pulse-chase experiment
In what direction is new mRNA synthesized?
5’ to 3’
What are the building blocks of RNA?
NTPs (nucleoside triphosphates GTP, CTP, UTP, ATP)
Does RNA polymerase need a primer to melt and unwind DNA?
No
What is the first step in prokaryotic transcription?
RNA polymerase binds DNA
Prokaryotic transcription: what happens after RNA polymerase binds the DNA?
RNA polyermase melts the DNA
When RNA polymerase melts DNA, what is created?
A transcription bubble
How does prokaryotic transcription end?
RNA polymerase eventually falls off of the DNA. DNA closes and RNA floats away
Is RNA pol processive (transcribes thousands of base pairs without falling off)?
Yes
Does RNA polymerase have exonuclease activity (proofreading)?
No
Where does RNA polymerase bind and start transcription?
The promoter sequence
What are the -35 and -10 regions?
Consensus sequences with similar basepairs that the RNA polymerase binds well
What is the +1 site in prokaryotic DNA?
The transcription start site, where the first nucleotide is transcribed
Is the consensus sequence sufficient for transcription?
Yes
Can transcription occur without the -35 sequence, -10 sequence, and the correct distance dividing them?
No
What points RNA polymerase in the correct direction for prokaryotic transcription?
Asymmetry of the promoter
Is one prokaryotic promoter enough to transcribe multiple genes?
No - each gene has its own promoter
Is the promoter upstream or downstream of the transcription start site?
Upstream
What happens to transcription when a promoter matches the consensus sequence well?
Transcription increases because RNA polymerase binds better
Does only one RNA polymerase act on a gene at a given time?
No, multiple RNA polymerases can act on a gene at the same time.
What kind of mutation occurs when deleting the -35 region?
Null
What kind of mutation occurs when making the promoter less similar to the consensus sequence?
Hypomorph
What kind of mutation occurs when making the promoter more similar to the consensus sequence?
Hypermorph
Can a DNA sequence be a promoter if an RNA strand of any length is synthesized?
Yes - even if it is shorter than predicted - because there may have been a terminator
