RNA Processing Flashcards
replication vs transcription
Replication: DNA synthesis, primer needed
Transcription: RNA synthesis, no primer
two major steps of molecular gene function
Transcription: RNA copy of a DNA gene
Translation: mRNA read by ribosome builds polypeptide sequence
where does transcription occur
in the nucleus
what is the RNA structure and function
single-stranded
ribose sugar instead of deoxyribose
RNA vs DNA synthesis
RNA does not need a primer
RNApol uses ribonucleotides instead of deoxyribonucleotides
3 main types of RNA and their functions
mRNA: made by transcription to carry genetic info to ribosomes
rRNA: helps form ribosomal subunits for translation of mRNA
tRNA: carries AA to ribosome and bind them to mRNA to build polypeptide chain
4 stages of transcription in bacteria
promoter recognition
transcription initiation
chain elongation
chain termination
promoter vs terminator
promoter-beginning of gene
terminator-end of gene
how many RNA polymerases catalyze bacterial transcription
1
what is needed to make the RNA polymerase holoenzyme
a sigma subunit
pribnow -10 and -35
-10: pribnow box (TATAAT)
-35: 6-bp region(TTGACA)
inverted repeats termination vs rut site
Intrinsic: presence of repeat forms single-stranded structure that loops and terminates transcription
Rut site: where rho-protein catches up to paused RNApol and releases mRNA and RNApol to terminate transcription
what is the main difference in transcription between eukaryotes and prokaryotes
eukaryotic mRNAs require processing to produce mature mRNAs
what 2 things control transcription regulation by influencing rate of transcription initiation
promoters
enhancers
3 steps of transcription initiation in eukaryotes
-eukaryotic promoter
-several transcription factors bind to DNA
-transcription initiation complex forms
3 types of RNA polymerase and what they transcribe
Pol I: rRNA
Pol II: mRNA and snRNA
Pol III: tRNA, 5S rRNA
3 eukaryotic promoter consensus sequences
-Goldberg:TATAAA
-CAAT box: found near -80
-GC rich box: -90 and upstream
3 types of post-transcriptional processing
5’ capping
3’ polyadenylation
intron splicing
what moves out into the cytosol after post-transcriptional processing
mRNA
how does alternative splicing generate transcript and protein diversity
mRNA exons can be spliced together in different orders to produce different base sequences
how does protein structure dictate function
different protein types perform different functions
what are 4 long non coding RNAs
telomerase RNA componant
X-inactivation specific transcript
ribonuclease P RNA
signal recognition particle RNA
3 main steps of transcription
initiation
elongation
termination
