Chapter 26 RNA Metabolism Part II

Question 1

Poly [A] tails aids in

Answer 1

mRNA stability and export to the cytoplasm

Question 2

Enzyme that aids in the addition of the poly [A] tail

Answer 2

Polyadenylate polymerase

Question 3

Role of polyadenylate polymerase in Poly A tail

Answer 3

catalyzes the addition of A residues to the free 3’-OH group by the reaction

Question 4

How can a gene give rise to multiple prodct?

Answer 4

Differential RNA processing

Question 5

Explain the process if alterative splicing

Answer 5

process where a specific exon could or could not be included into the mature mRNA transcript:

different protein isoforms are created

Question 6

What the percentage of human genes that go through alternative process?

Answer 6

> 95%

Question 7

Pre mRNA contains what for a;; the alternative processing pathways?

Answer 7

molecular signals

Question 8

RNA binding proteins promote what in alternative transcript production

Answer 8

promote one particular pathway

Question 9

Complex transcript can have mutiple…

Answer 9

sites where poly(A) tails
Poly A sites

Question 10

Benefits of alternative splicing and poly A site choices

Answer 10

Increases protein diversity made from higher eukaroyte geneomes

Question 11

In bacteria, a single 30s RNA PRECURSOR [PRE-rRNA] ecncodes for

Answer 11

16s
23s
5s rRNAS
and some tRNAS

Question 12

What do the rRNAs 16S and 23S contain

Answer 12

modified nucleotides

Question 13

make flashcards about rRNA splicing/processing

Answer 13

-

Question 14

how can we tell if its a RNA transcript?

Answer 14

Different types of rRNAs present

Question 15

Why are the rRNAs types important for treatment/therapy?

Answer 15

Helps with drug targeting

Question 16

make a flashcard about numeral ribosomal dif of pro and euk

Answer 16

-

Question 17

In eukaryotes where is the ribosomal rna processing initiated at?

Answer 17

nucleolus
a large complex that assembles on the rRNA precursor as it is synthesized

Question 18

Role of snoRNAs

Answer 18

guide modifications of rRNAs in ribosomes

Question 19

Whats in the nucleosis complex that processing occurs on?

Answer 19

Slide 62

Question 20

Common nucleoside modificatiosn inlcude

Answer 20

changing of uridine to pseudouridine

adomet-deopendent nucleoside methylation

Question 21

snoRNAs size and role

Answer 21

60-300 nucleotide RNAs that bind to rRNA to ID the modification site

Question 22

snoRNA-protein complexs [snoRNPs]

Answer 22

complexes of a snoRNA and proteins that carry out nucleoside modifications

Question 23

Box H/ACA snoRNPS

Answer 23

AID IN PSEUDOURIDILYATION

Question 24

Box C/D snoRNPS

Answer 24

aid in the 2’-o-methylation

Question 25

Most cells have how many distinct tRNAs

Answer 25

40-50

Question 26

Eukaryotic cells have mutiple copies of...

Answer 26

copies of the tRNA genes

Question 27

Where are transfer RNAs are derived from

Answer 27

longer rna precursors by enzymatic removal of nucletoides 5'-3'

Question 28

T/F All RNAs go through processing

Answer 28

True

Question 29

What enzyme removes RNAse P from RNA at the end?

Answer 29

endonuclease

Question 30

FINISH SLIDE 66

Answer 30

-

Question 31

Role of miRNAs

Answer 31

Regulate gene expression by degrading or stopping translation of mRNAs

Question 32

Structure of miRNAS

Answer 32

22 nucleotides long complemntary in sequence to particular mrna regions

Question 33

FINISH 68

Answer 33

-

Question 34

Where are some primary transcripts for miRNAs pri-miRNAs

Answer 34

encoded in then introns of other genes

Question 35

What mediates the processing of pri-miRNA

Answer 35

endoribonuclease doresha and dicer

Question 36

When is the target mrnna in mirna cleaved?

Answer 36

when the complementarity between mRNA and its target is nearly perfect

Question 37

What happens if the complemntarity is only partial [in miRNAs]?

Answer 37

Complex blocks translation of the target mRNA

Question 38

mAKE MIRNA PROCRESSING FLASHCARDS

Answer 38

SLIDE 70

Question 39

Cellular mRNAs are degraded at..

Answer 39

different rates

Question 40

the cellular conc. of miRNA depends on

Answer 40

the level of gene expression

Question 43

How does miRNA decay begins

Answer 43

one or several cuts by an endoribonuclease followed by degradation by an exoribonucleases

Question 45

What degrades miRNA?

Answer 45

Exoribonucleases

Question 47

Polynucleotide phosphorylase [PNPase] role?

Answer 47

exoribonuslces in charge of mRNAs degradation in bacteria chloroplast and mitochondria

Question 48

PNPase catalyze what

Answer 48

reversible phosphororolysis of mRNA using orthopjosphate as the nucleophile

Question 49

What removes hairpins during mRNA degradation?

Answer 49

PNPase

Question 50

Exosomes role

Answer 50

3' to 5' exoribonucleases in eukaryotes in charge of RNA degradation

Question 51

Exosomes locus and size

Answer 51

exist in the nucleus cytoplasm and nuclelous has 10 proteins

Question 52

Reverse transcriptase

Answer 52

an RNA depedent DNA polymerase

Question 53

Role of Reverse transcriptase

Answer 53

changes viral rna into DSdna [seen in retroviruses like HIV]

Question 54

The DNA created by reverse transcriptase is

Answer 54

usually integrated into the host genome

Question 55

3 activities of reverse transcriptase

Answer 55

1. synthesize the dna strain 2. degrade the rna strain 3. make another dna strain

Question 56

Restroviruses structure

Answer 56

3 genes and LTR Sequences

Question 57

Name the 3 genes of retroviruses

Answer 57

gag pol env

Question 57

Gag RETROVIRUSES GENE ROLE

Question 58

pol retroviruss gene role

Question 59

env retrovirus gene role

Question 60

LTR

Question 61

What does reverse transcriptase catalyze

Answer 61

RNA dependent DNA synthesis RNA degradation DNA dependent DNA synthesis

Question 62

What does DNA synthesis require

Answer 62

a primer

Question 66

What causes some retroviruses to grow cells abnormally

Answer 66

oncogene

Question 67

Onocgenes are classfied as

Answer 67

RNA tumor viruses -> causes cancer

Question 68

Retroverious HIV causes..

Answer 68

Aids

Question 69

Explain the virulence of retrovirus HIV

Answer 69

kILLS MANY OF THE CELLS IT INFECTS t LMYOPHOCYTES Supress the host immune syste,

Question 70

The reverse transcriptase of HIV is

Answer 70

very error prone

Question 71

In the retrovirus HIV what happens every time the genome is replicated?

Answer 71

an 1+ error in every time the genome is replicated

Question 72

What is the azidothymidine [AZT]

Answer 72

is a deoxythymidine analog [drug]

Question 73

How does azidothymidine AZT creation

Answer 73

concerted to AZT triphosphate inside T lymphocytes

Question 74

Explain AZT bidning affinity

Answer 74

AZT Triphopohsate have higher affinity to the HIV transcriptase

Question 75

AZT triphosphate inhibits and terminates what, respectively

Answer 75

inhibits dTTP binding Terminates viral DNA synthesis

Question 76

What has a similar mechanism of action to AZT triphosphate?

Answer 76

dideoxyinsoine

Question 77

Retrotransposons

Answer 77

eukaryotic DNA transposons with structures similar to ritovirus

Question 78

What's the similiar between transposons, retroviruses, and introns

Answer 78

common evolutionary oriign

Question 81

Homing process

Answer 81

DNA endonucleases promote intron insertion into a indetincal site ina homologous gene that doesnt have it

Question 84

Retrohoming

Answer 84

RNA INTRON IS PLACED INTOA DNA GENE FOLLOWED BY A PRODUCTION OF A DNA COPY BY A REVERSE TRANSCRIPOTASE

Question 85

Telemores are an RNP t/f TRUE

Question 86

Telomeres structures

Answer 86

end of the linear chromosomes

Question 87

Telomerase

Answer 87

RNP that maintains telomere length in eukaryotird

Question 88

T loops in telomeres

Answer 88

specialized structure that ...

Question 89

RNA Depedent RNA polymerase [RNA repliaase]

Answer 89

replicate rna in the host cell

Question 91

SHARE STRUCTURE HOMOLOGY

Answer 91

SLIDE 91

Question 92

What are ribozymes

Answer 92

RNA enzymes

Question 93

Examples of ribozymes

Answer 93

self splicing group 1 introns RNAse P hammerhead ribozyme

Question 94

Ribozytransesterifcaiton Phosphodiester bond cleavge me activities are based on what

Question 95

Inernal guide sequence

Question 97

What are the shared properties between ribzymes and enzymes

Answer 97

both speed upr eaction rates saturbale kinetcs [km kv] reaction specficity make use of substrate orientation,covalent catalysis and metla ctaylysis

Question 98

In vivio L-19 IVS is

Answer 98

not active (?)

Question 99

L-19 IVS gains catalytic activity when

Answer 99

THE FIRST 19 NUCLETOIDES ARE REMOVED [?}

Question 100

What is the L-19 IVS? What's it's role?

Answer 100

inervening seuence promotes nucleotidyl transfer reactions

Question 101

E. coli RNase P has what two componets?

Answer 101

RNA Component Protein component

Question 102

RNA component in E.col RNAse P

Question 104

Hammerhead ribozyme cataylyzes what

Answer 104

the hydrolysis of an internal phosphodiester bond

Question 105

What is the role of hammerhead ribozyme?

Answer 105

cleave RNA or virusoids[small RNAs associated with plant RNA viruses]

Question 106

What type of catalysis does the hammerhead ribozyme use?

Answer 106

general acid and base catalysis

Question 107

RNA World Hypothesis

Answer 107

proposed an acient RNA world where RNA was a genetic material AND a catlyst supported by riboxymes

Question 110

SELEX Method

Answer 110

rapidly searches pools of random rna polymers and extracts those with specific activities

Question 112

Explain how RNA enzymes can self sustain replicate

Answer 112

Two ribozymes can cross catalyse each other information.

Question 113

Key drugs targeting RNA Polymerases

Answer 113

Anthramycin D Rifampin A-amanitin