L03 DNA Transcription Flashcards
What is transcription
synthesis of RNA (mRNA)
What is translation
synthesis of protein using mRNA
What is the function of ribosomes?
sites of translation
they bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.
What is primary transcript
RNA transcript before processing
The coding strand of DNA has a different sequence from that of mRNA. (T/F)
False, the sense/coding strand of DNA has the same sequence as the mRNA (T instead of U).
The anticoding strand of DNA is complementary to mRNA and is used as the template for mRNA synthesis. (T/F)
True.
DNA being read = template, antisense, anti coding
RNA Transcript = same
DNA not being read = sense strand, coding strand
__________ ensures the proper location of transcription initiation
PROMOTER region of proykarytotic gene: located upstream of the RNA coding sequence, and ensures the proper location of transcription initiation.
Which direction does RNA polymerase catalyzes the synthesis of mRNA?
Which direction does it travel on the template strand?
RNA polymerase catalyzes the synthesis of an RNA molecule in the 5’ to 3’ direction along the 3’ to 5’ template/antisense/antiocoding strand of the DNA.
The coding strand or sense strand has the same sequences as the RNA. (T/F)
True
The prokaryote promoter sequences are generally found at ________________ bp from the transcription start site.
The prokaryote promoter sequences are generally found at -35 and -10 bp from the transcription start site.
What is the Pribnow box?
-10 consensus sequence: 5’-TATAAT-3’ (part of a promoter site on DNA for transcription to occur in bacteria
A primer is required for DNA and RNA (T/F)
False. A primer is only required for DNA.
What’s an holoenzyme?
core polymerase plus sigma factor used to synthesize PROKARYOTIC RNA
RNA polymerase I:
A. 5.8S, 18S, and 28S (rRNA genes)
B. all protein-coding genes (mRNA) and some snRNAs
C. tRNA genes and some snRNAs
RNA polymerase I: 5.8S, 18S, and 28S (rRNA genes)
RNA polymerase II:
A. 5.8S, 18S, and 28S (rRNA genes)
B. all protein-coding genes (mRNA) and some snRNAs
C. tRNA genes and some snRNAs
RNA polymerase II: all protein-coding genes (mRNA) and some SRNs
RNA polymerase III:
A. 5.8S, 18S, and 28S (rRNA genes)
B. all protein-coding genes (mRNA) and some snRNAs
C. tRNA genes and some snRNAs
RNA polymerase III: tRNA genes and some snRNAs
What is the significance of the RNA hairpin loop in prokaryotic RNA?
- The RNA hairpin loop causes physical stress on the enzyme complex which destabilizes the core polymerase’s hold on the RNA (prokaryotes)
- RNA is released
- Double helix reforms
What is the difference between prokaryotic and eukaryotic promoters?
Prokaryote’s promoter region:
- 35 consensus sequence = 5’-TTGACA-3’
- 10 consensus sequence = 5’-TATAAT-3’ (also called the Pribnow box)
Eukaryote Region:
GC box = GGGCGG (-70 to -200 bp)
CAAT box = CCAAT (-20 to -35)
TATA box = TATAAA (-80)
Not to be confused with DNA replication:
13-nucleotide sequences (three in tandem array)
9-nucleotide sequences (four are present).
TFIIE:
A. Causes a distortion in the DNA helix allowing the recruitment of other transcription factors.
B. Involved in RNA polymerase interactions and start site recognition (before polymerase)
C. Contains a DNA helicase to unwind DNA and activates RNA polymerase by phosphorylation
E. Involved in positioning RNA polymerase
E. Involved in positioning RNA polymerase
TFIIB:
A. Causes a distortion in the DNA helix allowing the recruitment of other transcription factors.
B. Involved in RNA polymerase interactions and start site recognition (before polymerase)
C. Contains a DNA helicase to unwind DNA and activates RNA polymerase by phosphorylation
E. Involved in positioning RNA polymerase
B. Involved in RNA polymerase interactions and start site recognition (before polymerase)
TFIIH:
A. Causes a distortion in the DNA helix allowing the recruitment of other transcription factors.
B. Involved in RNA polymerase interactions and start site recognition (before polymerase)
C. Activates RNA polymerase by phosphorylation
E. Involved in positioning RNA polymerase
C. Contains a DNA helicase to unwind DNA and Activates RNA polymerase by phosphorylation
TFIID:
A. Recruitment of other transcription factors.
B. Involved in RNA polymerase interactions and start site recognition (before polymerase)
C. Activates RNA polymerase by phosphorylation
E. Involved in positioning RNA polymerase
A. Causes a distortion in the DNA helix allowing the recruitment of other transcription factors.
__________________ are recruited to the promoter and transcription initiation site in eukaryotes.
RNA polymerase, TFIIE, and TFIIH
The RNA pol II and the transcription factors TFIIB (TAFs and TBP), and other transcription factors form the basal transcriptional machinery. (T/F)
False, The RNA pol II and the transcription factors “TFIID” (TAFs and TBP), and other transcription factors form the basal transcriptional machinery.