Trans - Gene Expression

Question 1

retroviruses

Answer 1

RNA viruses that make DNA copies of themselves by using reverse transcriptase

Question 2

reverse transcriptase

Answer 2

enzyme that creates DNA from RNA template

Question 3

retrotransposons

Answer 3

sequences of DNA that make RNA copies of themselve, then get reverse-transcribed into DNA

Question 4

operons - type/level of control

Answer 4

transcriptional control

Question 5

operons

Answer 5

functioning unit of genomic DNA containing a cluster of genes under the control of a single regulatory signal or promoter

Question 6

enzyme for transcription

Answer 6

RNA polymerase

Question 7

subunits of RNA polymerase [5]

Answer 7

[1] alpha1
[2] alpha2
[3] beta'
[4] beta
[5] omege

Question 8

alpha1 subunit of RNA polymerase

Answer 8

assembling of RNA polymerase complex

Question 9

alpha2 subunit of RNA polymerase

Answer 9

assembling of RNA polymerase complex

Question 10

beta’ subunit of RNA polymerase

Answer 10

template binding

Question 11

beta subunit of RNA polymerase

Answer 11

catalytic subunit for RNA synthesis

Question 12

enzyme catalyzed by beta subunit of RNA polymerase

Answer 12

5’ –> 3’ polymerase

Question 13

omega subunit of RNA polymerase

Answer 13

unclear function

Question 14

subunits of eukaryotic RNA polymerase

Answer 14

2 alpha, 2 beta, omega, 7 more

Question 15

RNA polymerase I

Answer 15

synthesis of rRNA (28S, 18S, 5.8S)

Question 16

RNA polymerase II

Answer 16

synthesis of mRNA

Question 17

RNA polymerase III

Answer 17

synthesis of tRNA, snRNA, 5S rRNA, misc RNAs

Question 18

raw materials for new RNA

Answer 18

ATP, CTP, GTP, UTP

Question 19

direction of transcription

Answer 19

5’–>3’

Question 20

processes involved in transcription

Answer 20

initiation, elongation, termination

Question 21

relationship of chromatin structure to gene expression

Answer 21

open chromatin –> increased gene expression

Question 22

transcription unit

Answer 22

transcribed segment of DNA

Question 23

promoter regions [3]

Answer 23

[1] TATA box
[2] CAAT box
[3] GC box

Question 24

classes of transcription factors [3]

Answer 24

[1] basal components
[2] activators
[3] corregulators

Question 25

basal components

Answer 25

allow transcription to take place at lower levels

Question 26

examples of basal components

Answer 26

TBP, TFIIA, B, E, F, H

Question 27

activators

Answer 27

bind to distal regulatory elements - enhancers

Question 28

corregulators

Answer 28

bind to distal regulatory elements - enhancers

Question 29

examples of activators

Answer 29

TFIID

Question 30

examples of corregulators

Answer 30

SP1, atf, ctf, ap1

Question 31

TFIID

Answer 31

recognizes TATA box, activator

Question 32

TFIIH

Answer 32

helicase - unwinds DNA; kinase - phosphorylates polymerase

Question 33

TFIIF

Answer 33

brings polymerase to promoter

Question 34

Sp1

Answer 34

recognizes GC box

Question 35

CTF

Answer 35

recognizes CAAT box

Question 36

antisense strand

Answer 36

DNA strand used as a template for transcription

Question 37

sense strand

Answer 37

DNA strand almost identical to the mRNA transcribed

Question 38

uracil replaces what base in RNA

Answer 38

thymine

Question 39

direction of RNA synthesis

Answer 39

5' --> 3'

Question 40

direction of reading of antisense strand

Answer 40

3'-->5'

Question 41

snRNA

Answer 41

function in splicing of mRNA

Question 42

snoRNA

Answer 42

used to process and chemically modfiy rRNA

Question 43

rRNA

Answer 43

ribosomal components

Question 44

tRNA

Answer 44

binds and carries amino acids to ribosome

Question 45

mRNA

Answer 45

codes for proteins

Question 46

composition of 5' cap

Answer 46

7-methylguanosine

Question 47

responsible for adding GMP to 5' end in capping

Answer 47

guanylyltransferase

Question 48

responsible for methylation of terminal guanine in capping

Answer 48

guanine-7-methyltransferase

Question 49

linkage of 5' cap

Answer 49

5'-->5' triphosphate linkage

Question 50

importance of capping [2]

Answer 50

[1] stabilize mRNA | [2] allows exit of mRNA from nucleus

Question 51

responsible for synthesizing poly-A-tail

Answer 51

polyadenylate polymerase

Question 52

before adding the poly-A-tail, where is the mRNA cleaved?

Answer 52

consensus sequence called the polyadenylation signal sequence (AAUAA)

Question 53

importance of poly-A-tail [4]

Answer 53

[1] stabilize mRNA [2] facilitate exit from nucleus [3] aid in translation [4] protection from exonucleases

Question 54

responsible for removal of introns

Answer 54

spliceosome

Question 55

snRNP

Answer 55

small nuclear ribonucleoprotein particle; involved in formation and function of spliceosome

Question 56

primary helper of mRNA exit from nucleus

Answer 56

Met 67-Mtr 2

Question 57

miRNA

Answer 57

short nuclear ribonucleic acid with no introns found in eukaryotic cells

Question 58

Drosha

Answer 58

removes 5'cap and poly-A-tail from miRNA

Question 59

exportin-5

Answer 59

removes miRNA from nucleus

Question 60

dicer

Answer 60

cuts pairs and unwinds structure of miRNA

Question 61

Argonaut protein

Answer 61

end product of miRNA transport

Question 62

responsible for attachment of amino acids to corresponding tRNAs

Answer 62

aminoacyl-tRNA-synthetase

Question 63

ribosomal binding sites

Answer 63

A, P, E

Question 64

A site

Answer 64

aminoacyl site; binds incoming tRNA

Question 65

P site

Answer 65

peptidyl site; carries peptidyl tRNA carrying the chain of amino acids already synthesized

Question 66

E site

Answer 66

exit site; carries empty tRNA

Question 67

energy requirements of translation

Answer 67

2 ATP, 2 GTP

Question 68

direction of reading of mRNA

Answer 68

5' --> 3'

Question 69

wobble hypothesis

Answer 69

base at the 5' end of the anticodon (first base of anticodon) allows nontraditional pairing with the base at the 3' end of the codon (last base of codon)

Question 70

significance of wobble hypothesis

Answer 70

single tRNA can recognize more than 1 codon

Question 71

protein is synthesized from what end to what end

Answer 71

amino terminal to carboxy terminal

Question 72

coupled system of translation and transcription

Answer 72

found in prokaryotes; translation happens as the mRNA is being transcribed

Question 73

polycistronic

Answer 73

several coding regions in single mRNA - each coding region has its own initiation and termination codon producing a separate species of polypeptide

Question 74

monoscistronic

Answer 74

only one coding region per mRNA - each mRNA codes for only one polypeptide

Question 75

shine-dalgarno sequence

Answer 75

purine-rich sequence upstream of AUG, can bind to ribosomes to put ribosomal subunits closer to AUG

Question 76

initiation codon

Answer 76

initiation codon recognized by initiator tRNA - directly goes to the P site

Question 77

amino acid carried by initiator tRNA in bacteria and mitochondria

Answer 77

N-formylated methionine

Question 78

amino acid carried by initiator tRNA in eukaryotes

Answer 78

methionine

Question 79

elongation factors in eukaryotes

Answer 79

EF-1alpha-GTP and EF-1beta-gamma

Question 80

responsible for catalysis of peptide bonds

Answer 80

peptidyltransferase

Question 81

proteins recognizing stop codon in prokaryotes

Answer 81

RF1, RF2, RF3-GTP

Question 82

RF1

Answer 82

recognizes UAA, UAG

Question 83

RF2

Answer 83

recognizes UAA, UGA

Question 84

RF-3-GTP

Answer 84

releases RF1 or RF2

Question 85

release factors

Answer 85

hydrolyze bond linking peptide to tRNA at P site

Question 86

polysome

Answer 86

single mRNA translated by more than one ribosome