RNA And Processing Of mRNA

Question 1

____ _____ within the same RNA strand results in secondary structure of RNA. In contrast, DNA is always a right handed double helix.

Answer 1

Base pairing

Question 2

Tertiary structure of RNA is driven by unconventional _____ _____.

Answer 2

Base pairing

Question 3

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.

Answer 3

RNA polymerase

Question 4

The____ strand has the same sequence as the RNA transcript. The _____ strand has the same sequence as the template strand.

Answer 4

Sense
Antisense

Question 5

DNA transcription uses RNA polymerase to go from ____ to _____. DNA replication uses DNA polymerase to go from ___ to ____.

Answer 5

DNA to RNA
DNA to DNA

Question 6

DNA transcription occurs throughout the cell cycle but primarily in _____ and ____ phase. DNA replication occurs during ____ phase.

Answer 6

G1and G2
S

Question 7

All RNA is synthesized in the ____. _____ is a type of messenger RNA that encodes for proteins. ______ include rRNA tRNA and miRNA

Answer 7

Nucleus
mRNA
NON-CODING RNA (ncRNA)

Question 8

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.

Answer 8

Ribosomal
Transfer

Question 9

The process of translation occurs in _____.

Answer 9

Ribosomes

Question 10

In ______ cells, one mRNA codes for multiple proteins.

Answer 10

Prokaryotic

Question 11

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.

Answer 11

eukaryotic
CAP
polyA

Question 12

_____ are non-coding regions of pre-mRNA and must be spliced out before the RNA can leave the nucleus

Answer 12

Introns

Question 13

In ____ cells, one RNA codes for one type of protein.

Answer 13

Eukaryotic

Question 14

RNA polymerase II carries RNA modifying factors on its ____ ____. The five prime end of mRNA is ____ while emerging from RNA polymerase II.

Answer 14

CTD tail
Capped

Question 15

_________ signals a sequence that the end of transcription is near. A poly a tail is then added to the 3’ end.

Answer 15

AAUAAA

Question 16

The ______ allows the cell to distinguish between mRNA, and other non-coding RNA since the other RNA does not contain the five prime cap

Answer 16

5’ cap

Question 17

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.

Answer 17

3’
30

Question 18

The coding region of DNA is called ____ , often a small part of a gene. The rest is introns

Answer 18

Exons

Question 19

Intron-exon boundaries are marked by key ______ _____. Introns start with ____ and end with _____. Exons start with ____ and end with ____.

Answer 19

Conserved sequences
GU AG
G. AG

Question 20

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.

Answer 20

Adenine
Nucleophilic attack
Nucleophilic attack

Question 21

Mature mRNAs contain only ____, not introns.

Answer 21

Exons

Question 22

A spliceosome is composed of over 200 different proteins, and _____.

Answer 22

Small nuclear ribonucleoproteins (snRNPs)

Question 23

_____ are responsible for splicing of introns.

Answer 23

Spliceosome

Question 24

One purpose of splicing is thought to promote genetic ____ . There are different combinations of introns and exons called ____ splicing.

Answer 24

Complexity
Alternative

Question 25

Alternative splicing relies on splicing, silencers and enhancers. regulators of splicing repression include ____, ____, and ____ _____. Regulators of splicing activation include ____, ____, and ____ proteins.

Answer 25

ISS (intronic splicing silencer)
ESS (exonic splicing silencer)
hnRNP ribonucleoprotiens

ISE (inTronic splicing enhancer)
ESE (exonic splicing enhancer)
SR proteins

Question 26

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.

Answer 26

Proteins
Exon junction complex

Question 27

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.

Answer 27

Nonsense mediated decay
Stop codons

Question 28

Review, take home message

Answer 28

Review