EXAM 3- Ch. 7 RNA PROCESSING

Question 1

what components are required for eukaryotic mRNA processing

Answer 1

• 5’ cap
• 3’ poly A tail
• rna splicing

Question 2

true or false: most rna’s must be further processed before they can carry out their roles

Answer 2

true

Question 3

any modification made to rna between its transcription and its final function in the cell. term?

Answer 3

rna processing

Question 4

can prokaryotes or eukaryotes translate mRNA as soon as it is transcribed by rna polymerase

Answer 4

prokaryotes

Question 5

what is a consequence of prokaryotes translating mRNA as soon as it is transcribed

Answer 5

very little processing of prokaryotic mRNA

Question 6

true or false: both eukaryote and prokaryotes process their rRNA and tRNA in different ways

Answer 6

false

Question 7

during prokaryotic processing is mRNA processed

Answer 7

no

Question 8

multiple genes transcribed on one transcript. term?

Answer 8

operon

Question 9

transcription unit of prokaryotic processing

Answer 9

operon

Question 10

what kind of proteins are translated from mRNA in prokaryotes

Answer 10

individual

Question 11

during eukaryotic processing what is produced

Answer 11

• mRNA
• tRNA
• rRNA

Question 12

one gene transcribed on one transcript. term?

Answer 12

monocystronic

Question 13

where does eukaryotic processing occur

Answer 13

nucleus

Question 14

what does UTR stand for

Answer 14

untranslated region

Question 15

what is the 1st modification in mRNA processing eukaryote

Answer 15

5’ rna capping

Question 16

what makes the 3’ end poly a tail

Answer 16

rna processing enzymes

Question 17

RNA splicing function eukaryote

Answer 17

removes intron sequences from newly transcribed pre-mRNA

Question 18

what signals where splicing occurs in eukaryotes

Answer 18

nucleotide sequences

Question 19

what does the splicing in eukaryotes

Answer 19

spliceosome

Question 20

how does the spliceosome work

Answer 20

uses atp hydrolysis to produce a complex series of RNA-RNA rearrangements

Question 21

what splices a small fraction of intron sequences in animals and plants

Answer 21

snRNPs

Question 22

what is selectively exported from the nucleus eukaryote

Answer 22

mature mRNAs

Question 23

what does the nucleus produce

Answer 23

ribosomes

Question 24

where will rRNA be edited

Answer 24

Nucleus

Question 25

modified guanine with methyl group by the formations the triphosphate bridge

Answer 25

5' cap

Question 26

what adds the 5' cap

Answer 26

capping enzymes

Question 27

what are the 4 functions of the 5' cap

Answer 27

- ID 5' end mRNA - protect from exonuclease - assist in export - assist in binging to ribosome

Question 28

what are the 2 capping enzymes activities

Answer 28

- phosphatase | - methyl transferase

Question 29

about how many adenines get added to the 3' end by 3' poly A tail

Answer 29

200

Question 30

location of 3' poly A tail

Answer 30

around 30 nucleotides from cleavage signal

Question 31

is a template needed for 3' poly A tail

Answer 31

no

Question 32

2 functions of 3' poly A tail

Answer 32

- assisted in export out of nucleus | - protects against degradation by exonuclease

Question 33

def: the removal of introns from pre-mRNA and join of exons to form mRNA

Answer 33

splicing

Question 34

what 3 things are required for splicing

Answer 34

- splisosome - consensus sequences - ATP

Question 35

what do consensus sequences mean

Answer 35

similar in all species

Question 36

true or false: rna has catalytic activity

Answer 36

true

Question 37

what is the splicesosome made of

Answer 37

large complex of snRNPs

Question 38

in the splicesosome what recognizes consensus sequences on pre-mRNA

Answer 38

U1 and U2

Question 39

in the splicesosome what binds consensus sequences on pre-mRNA

Answer 39

U4, U5, U6

Question 40

rna- rna =

Answer 40

- confirms splice site | - check splicing accuracy

Question 41

what occurs in splicing rxn

Answer 41

- exchange of 2 alcohol groups in 2 transesterification rxn

Question 42

in an transesterification rxn (1) what does the branch point react with

Answer 42

5' of intron

Question 43

in an transesterification rxn (1) what bonds are broken

Answer 43

phosphodiester

Question 44

in an transesterification rxn (1) the intron end covalently binds to what

Answer 44

a branch

Question 45

in an transesterification rxn (2) what does the 3' end of first exon react with

Answer 45

5' end of second exon

Question 46

what forms at the end of a transesterification rxn

Answer 46

lariat

Question 47

what kind of modifications are in tRNA

Answer 47

chemical changes

Question 48

rRNA maturation requires

Answer 48

- cleavage and chemical modification

Question 49

what does the mature mRNA have to bind to for export to the cytoplasm

Answer 49

proteins/ nuclear transport receptors

Question 50

where and how does the mature mRNA come out of

Answer 50

nuclear pore complex | active transport

Question 51

what life on earth was before DNA

Answer 51

pre-RNA

Question 52

in eukaryotes what is the advantage of non coding sequences

Answer 52

alternative splicing

Question 53

what % are exons in DNA

Answer 53

1%

Question 54

what % are introns in DNA

Answer 54

20%

Question 55

what are the advantages of alternative splicing

Answer 55

- producing different proteins from a single gene - more proteins - specific proteins