RNA And Processing Of mRNA Flashcards
____ _____ within the same RNA strand results in secondary structure of RNA. In contrast, DNA is always a right handed double helix.
Base pairing
Tertiary structure of RNA is driven by unconventional _____ _____.
Base pairing
One strand of the DNA helix is used as a template for transcription. ______ ______ synthesizes a complementary RNA strand in a five prime to three prime direction.
RNA polymerase
The____ strand has the same sequence as the RNA transcript. The _____ strand has the same sequence as the template strand.
Sense
Antisense
DNA transcription uses RNA polymerase to go from ____ to _____. DNA replication uses DNA polymerase to go from ___ to ____.
DNA to RNA
DNA to DNA
DNA transcription occurs throughout the cell cycle but primarily in _____ and ____ phase. DNA replication occurs during ____ phase.
G1and G2
S
All RNA is synthesized in the ____. _____ is a type of messenger RNA that encodes for proteins. ______ include rRNA tRNA and miRNA
Nucleus
mRNA
NON-CODING RNA (ncRNA)
rRNAs are ______ RNAs that form the basic structure of the ribosome in catalyze protein synthesis. tRNAs are _____ RNAs and are central to protein synthesis as adapters between mRNA and amino acids.
Ribosomal
Transfer
The process of translation occurs in _____.
Ribosomes
In ______ cells, one mRNA codes for multiple proteins.
Prokaryotic
In _____ cells, mRNA is transcripted by RNA polymerase II. Pre-mRNA processing must occur, including adding a _____ to the 5’ end of pre-mRNA and adding a ____ to the 3’ end of pre-mRNA.
eukaryotic
CAP
polyA
_____ are non-coding regions of pre-mRNA and must be spliced out before the RNA can leave the nucleus
Introns
In ____ cells, one RNA codes for one type of protein.
Eukaryotic
RNA polymerase II carries RNA modifying factors on its ____ ____. The five prime end of mRNA is ____ while emerging from RNA polymerase II.
CTD tail
Capped
_________ signals a sequence that the end of transcription is near. A poly a tail is then added to the 3’ end.
AAUAAA
The ______ allows the cell to distinguish between mRNA, and other non-coding RNA since the other RNA does not contain the five prime cap
5’ cap
Once, in the cytoplasm mRNA is gradually chewed up from the ____ end by exonucleases, the _____ tail gets shorter and shorter. The average mRNA, half life is about ____ minutes.
3’
30
The coding region of DNA is called ____ , often a small part of a gene. The rest is introns
Exons
Intron-exon boundaries are marked by key ______ _____. Introns start with ____ and end with _____. Exons start with ____ and end with ____.
Conserved sequences
GU AG
G. AG
The branch point nucleotide is almost always an ____. The branch point adenine performs a _____ ____ at the 5’ splice site. Then the free 3’ OH group at the exon performs a _____ ____ at the 3’ splice site.
Adenine
Nucleophilic attack
Nucleophilic attack
Mature mRNAs contain only ____, not introns.
Exons
A spliceosome is composed of over 200 different proteins, and _____.
Small nuclear ribonucleoproteins (snRNPs)
_____ are responsible for splicing of introns.
Spliceosome
One purpose of splicing is thought to promote genetic ____ . There are different combinations of introns and exons called ____ splicing.
Complexity
Alternative
Alternative splicing relies on splicing, silencers and enhancers. regulators of splicing repression include ____, ____, and ____ _____. Regulators of splicing activation include ____, ____, and ____ proteins.
ISS (intronic splicing silencer)
ESS (exonic splicing silencer)
hnRNP ribonucleoprotiens
ISE (inTronic splicing enhancer)
ESE (exonic splicing enhancer)
SR proteins
Mature RNAs are decorated with ____. This is how the cell knows they are ready for export. The ___ ____ ____ marks successfully spliced junctions and is a good marker of a mature RNA.
Proteins
Exon junction complex
One of the mechanisms that regulates mature RNAs is ___ ___ ___. If an mRNA has ____ ____ upstream from the exon junction complexes, this system catches it and destroys it in the cytosol.
Nonsense mediated decay
Stop codons
Review, take home message
Review
