Transcription Flashcards
RNA Polymerase I synthesizes
rRNA
RNA Polymerase II synthesizes
mRNA, miRNA, parts of the spliceosome
RNA Polymerase III synthesizes
tRNA and the 5S rRNA gene
RNA polymerase II moves in what direction?
5’ to 3’
What are the two most common promoter sequences?
TATA and CpG islands
What General Transcription Factor (GTF) is REQUIRED for initiation?
TFIID
What is the mechanism of TFIID to cause initiation of transcription?
TFIID binds to the promoter (causing a sharp bend in the DNA) then multiple other GTF’s (see slides for specific details) bind to each other creating a large physical marker to allow RNA Pol II to find the promoter that requires transcription
What is the difference between Differential Transcription factors and Master Regulatory factors?
Differential Transcription factors regulate genes by binding to the enhancer or repressor and ensures the right amount of transcription occurs in the right kind of cell; Master regulatory factors send out transcription factors to multiple other genes for simultaneous and coordinated transcription
True or False… Are genetic disorders caused only within the exons of DNA?
False, defects with non-coding areas such as transcription factors and promoter regions etc…
What are the 3 key events needed in mRNA processing?
Addition of a 7-methylguanosine 5’ cap, addition of a Poly A 3’ tail and splicing
What is the function of the Exon Junction Complex, EJC?
The EJC checks the mRNA for a cap, tail and correct sequence prior to the mRNA exiting the nucleus
What are three examples of diseases caused by mutations in non coding DNA
Crohn’s, Psoriasism Type I Diabetes
True or False: Prokaryotic DNA contains introns
False, no introns, no splicing
Why does Prokaryotic mRNA not contain caps or tails
There is no nucleus so it already structured to
