Chapter 5: Transcription Flashcards
RNA polymerase??
- DNA dependent RNA polymerase
Transcription is what?
ran synthesis
RNA polymerase has a template of ____ (non coding strand)
- ssDNA
the Gene is what?
coding strand/ non template
RNA polymerase uses / strand of DNA to create the transcript..
noncoding/template
Ex: Question : RNA?
5’ AGACTCC 3’
5’ AGACTCC 3’ (coding DNA sequence)
3’ TCTGAGG 5’ (template)
5’ AGACTCC 3’ (primary transcript …it is the exact sequence of the coding sequence..)
mRNA??
- messenger RNA
- transcript of protein coding genes
tRNA??
- transfer RNA
- brings amino acid to ribosome during translation
rRNA??
- ribosomal RNA
- component of the ribosome which translates mRNA
snRNA???
-responsible for eukaryotic mRNA processing
Anything to the left is ___ of the gene. Anything to the right is ___ of the gene. NO MATTER HOW YOU ARE LOOKING AT THE GENE.
- upstream
- downstream
Three steps in transcription??
- Initiation
- Elongation
- termination
Steps of Transcription(prokaryotes) : 1. Initiation L>Promoter?? also called the _ spot. L> location? L> RNA Poly? L> what does the promoter sequence serve as?
- a sequence upstream of the start of the gene that encodes the RNA. The RNA polymerase interacts with the promoter
L> + 1 spot
L> the promoter sequence serves to orient the RNA poly to start transcribing at the beginning of the gene and ensures that the initiation of synthesis of every RNA occurs at the same time
Steps of Transcription(prokaryotes) :
1. Initiation
L>RNA coding sequence?
- the DNA sequence transcribed by RNA Polymerase into the RNA transcript
Steps of Transcription(prokaryotes) :
1. Initiation
L>Terminator??
- specifying where transcription stops.
Steps of Transcription(prokaryotes) :
1. Initiation
L>What type of RNA polymerase is found in bacteria?
- ONE KIND
- Holoenzyme which consists of core enzymes
( bound to 2 alpha, beta and beta prime polypeptide)
Steps of Transcription(prokaryotes) :
1. Initiation
L>The RNA polymerase (holoenzyme) is bound to what polypeptide?
- Sigma factor which ensures that RNA polymerase binds in a stable way only at PROMOTE REGIONS.
L> it is not required for elongation and termination stages of transcription
Steps of Transcription(prokaryotes) :
1. Initiation
L>RNA polymerase binds more tightly to the promoter at ___ region accompanied by the local untwisting go the DNA in that region.
- -10 region which is upstream from the +1 promoter region
Steps of Transcription(prokaryotes) :
1. Initiation
L>Sigma factor binds to what two regions of promoter?
- -35 and -10
Steps of Transcription(prokaryotes) :
1. Initiation
L>RNA synthesis does not need a ___.
L> Once transcribing has begun what is released?
- primer
- sigma factor
Steps of Transcription(prokaryotes) :
1. Elongation
L> after initiation has occurred the RNA polymerase beings ??
- moving along the DNA and the sigma factor is released.
Steps of Transcription(prokaryotes) :
2. Elongation
L> During this stage the RNA polymerase does what?
L> moves along?
L> behind the untwisted region what exists?
L> what occurs there
L> what exists the enzyme?
- it moves along untwisting DNA double helix ahead of itself exposing a new segment of single stranded template DNA.
L> behind the untwisted region the two DNA strands reform into a double strand…..within the untwisted region about 9 RNA nucleotides are base paired to the DNA in a temporary RNA-DNA hybrid, the rest of the newly synthesized RNA exits the enzyme as a SS.