Younger Transcription Flashcards
Enzyme responsible/ involved in making transcript.
RNA polymerase
True/False: RNA polymerase doesn’t need a primer.
True
RNA polymerase reads template strand from __ to __.
3’ to 5’
RNA polymerase synthesizes RNA transcript from __ to __ using ribonucleotides (NTPs)
5’ to 3’
True/False: RNA polymerase recognizes termination signals.
True
DNA coding strand base sequence is identical to the RNA transcript sequence, except RNA has what?
RNA has U’s instead of T’s
Determine template strand and mRNA of ATGGGGCTCAGCGAC
template: TACCCCGAGTCGCTG (complimentary)
mRNA: AUGGGGCUCAGCGAC (same except U for T)
What is the role of the sigma factor?
identifying promoter sequences on DNA and recruits core enzyme into proximity and dissociates from the core enzyme after transcription begins
True/False: Sigma factor can turn on any gene that it wants to.
False: Not every gene can be turned on by a single sigma factor… Different sigma factors recognize different types of promoter sequences
What are the 2 consensus sequences that are recognized by sigma factor?
TATA box (-7 nucleotides upstream) -35 sequence
Scanning and recognizing of promoter sequence cues by the holoenzyme trigger _____________.
Transcription initiation
Another name for TATA box is?
Pribnow box
Pyrophosphate is further cleaved in irreversible reaction by what enzyme?
2 high energy bonds are cleaved
Pyrophosphatase
Rho-dependent termination requires ________
an additional protein
Prokaryotic mRNAs can be ________ (ie one mRNA can code for several proteins)
polycistronic
Shine dalgarno sequence does what?
Start site for translation… Ribosome recognizes this 5’ UTR region
Eukaryotic mRNAs are ALWAYS _________.
Monocistronic
This is an antibiotic that prevents transcription initiation/elongation by binding to RNA polymerase which used to treat tuberculosis. (THIS WILL BE A QUESTION)
Rifampin
Eukaryotic DNA is highly condensed and is called?
Chromatin
What is the less condensed form of DNA and is more accessible to RNA polymerases (thus more transcripts)
Euchromatin
One of the things that distinguishes phenotypes among twins are based on epigenetics that is from what?
Methylation of DNA
each polymerase transcribes precursors to what???
RNA polymerase I
RNA polymerase II
RNA polymerase III
1- rRNA
2-hnRNA (precursor to mRNA)
3-tRNA
RNA pol II recognizes what two consensus sequences?
TATA box (-25) CAAT box (-70)
rRNA synthesis: 3 rRNAs are transcribed as a single large precursor by
RNA pol I in the nucleolus
Individual rRNAs are cleaved apart by what?
RNases
What are the major differences of Prokaryotes and Eukaryotes in RNA synthesis.
Promoter region in Eukaryotes has a CAAT box
Eukaryotes have exons and introns
WHat does the 3’ poly A tail do?
helping release transcript from the ribosome
WHat does the 5’ capping at the end of mRNA do?
Serves as a ribosome recognition signal and stabililzes mRNA
What is the removal of introns and the joining of exons by snRNPs?
Splicing
_____ are composed of snRNAs, they from a lariat (loop), it gets clipped out and join the exons.
snRNPs
What is the excised intron?
Lariat
Systemic lupus erythematosus is an autoimmune disease that recognize host proteins, including snRNPs… When/ who is it often observed in?
Late-teen females
Amanita phalloides- the death cap mushroom has Alpha-amanitin- which does what?
Alpha-amanitin binds to RNA and polymerase-II inhibits mRNA synthesis.
