Practice Questions Flashcards

1
Q

Keq negative

A

rxn rate goes forward

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2
Q

Keq positive

A

rxn reverse

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3
Q

Combustion rxn

A

exothermic
-∆G
+∆S
-∆H

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4
Q

ATP is ______ bond

A

phosphoanhydraide bond

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5
Q

lipids store more energy than carbs because

A

they have central carbon of lipids own a greater number of valence electrons

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6
Q

MMR is clinically related to

A

hereditary non-polyposis colorectal cancer

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7
Q

BER is associated with

A

glycolysis

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8
Q

Excision endonuclease action

A

cleaves damaged DNA at either side of lesion

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9
Q

DNA gyrase function

A

prevents supercoiling of double helix

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10
Q

DNA pol III action

A

3’–5’ of template DNA strand

exonuclease proofreading

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11
Q

RNA primers are removed by

A

3’–5’ pol I exonuclease

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12
Q

craniosynostosis is associated with

A
homeodomain
MSX2 (Boston type)
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13
Q

Rubenstein-Tayi is associated with

A

haploinsuffieciency of CREB binding protein (CRB)

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14
Q

CRB is a

A

HAT

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15
Q

NFAT is triggered to ______

A

enter nucleus in the presence of high intracellular Calcium

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16
Q

doxorubicin (adriamycin) is a

A

chemo drug that blocks DNA replication in dividing cells by intercalation

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17
Q

overabundance of eIF4E cap protein will

A

lead to over expression of proteins coded by mature mRNA

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18
Q

3’ AG is bound by

A

U2AF

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19
Q

5’GU is bound by

A

U1 snRNA

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20
Q

branch a point binds

A

U2 snRNA

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21
Q

rifampicin action

A

inhibits transcription of DNA by blocking Pol II at its exit channel

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22
Q

scurvy

A

proline

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23
Q

western blot uses

A

antibodies as reagent in gel electrophoresis

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24
Q

3’ poly A tail is added by 2 successive enzymatic step first is ____
what code?

A

endonucleolytic cleavage of mRNA and polyadenylation of newly generated 3’ OH terminus

endonuclealytic cleavage of RNA occurs at highly conserved sequence

AAUAAA

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25
Q

okazaki fragment is initiated by

A

DNA primase synthesizes a short oligonucleotide that is extended by DNA poly to form okazaki fragment

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26
Q

activation domains

A

some act to recruit co-activators that modify chromatin

others medicate protein-protein interactions needed to recruit general transcription machinery

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27
Q

at equilibrium, ∆G =

A

0

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28
Q

Which is not required for DNA replication and RNA transcription

A

Primers not required for RNA transcription

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29
Q

What is required for DNA replication and RNA transcription

A

RNA
DNA
Proteins

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30
Q

5’ splice site is recognized by

A

U1 snRNA

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31
Q

ATM protein is involved in

A

DNA damage check point

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32
Q

Next gen enzyme

A

DNA poly

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33
Q

Fidelity of DNA replication at DNA replication fork comes from inherent accuracy of active site of replicative DNA poly to select correct incoming dNTPs. 3’-5’ proofreading of DNA poly to exercise incorrect

A

mismatch DNA repair

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34
Q

Many biochemical runs that occur in human cells catalyzed by dehydrogenase enzymes. Change in free energy resulting from rxn depends upon:

A
  1. emf or reduction potential (∆E)
  2. relative affinity of electron acceptor for electron donated by electron donor
  3. concentration of electron acceptor and electron donor in cell
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35
Q

SDS separates based on

A

size (kd)of protein

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36
Q

RNA pol makes

A

rRNA 18S, 28S, 5.8S

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37
Q

swi/snf

A

ATP hydrolysis allows DNA contacts to be be broken so histone can move along DNA

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38
Q

G1 phase

A

cell divide and growth in g1 phase

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39
Q

NER clinical

A

XP

Tric

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40
Q

BER is initiated by

A

N-glycosylase

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41
Q

PCR temp is

A

higher than DNA melting temp

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42
Q

enzymatic activity XPB is

A

ATP dependent helices that opens DNA

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43
Q

beta amylase is made by

A

B-secretase followed by Gamma-secretase action of B-amyloid precursor protein

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44
Q

TATA box binding protein

A

helps direct assembly of pre-initiation complex at promotor

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45
Q

HR is

A

dependent on availability of sister chromatid

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46
Q

alpha helix and bet sheets are

A

H bonds

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47
Q

DNA poly 3’–5’ exonuclease

A

trans-lesion DNA synthesis repair

48
Q

cyclosporin enzyme activity

A

peptide prolyl cis- isomerase activity

49
Q

first enzymatic step in cap addition is

A

triphosphatase

50
Q

mushroom, alpha amatin inhibits

A

blocks RNA chain elongation by preventing translocation of RNA poly along DNA

51
Q

initial phase translation at 30S subunit attaches to

A

Shine-Delgarno sequence with 16 S rRNA

52
Q

purpose of NaOH in southern blot

A

denatures DNA frag in gel so probe can subsequently hybridize to it complementary

53
Q

What leads to double stranded breaks in genome?

A
  1. bleomycin treatment for cancer
  2. HIV infection
  3. spermatogenesis
  4. CT scan
54
Q

What does not lead to double standed DNA break

A

UV exposure

55
Q

Capping 5’ end of newly synthesized mRNA protects 5’ end from exonucleolytic degradation

A
  1. during capping guanosine residue is added to 5’ end of mRNA backwards
  2. capping precedes polyadenylation of 3’ end of mRNA
  3. e1F4e binds cap, which is critical for translocation of mRNA
56
Q

tamoxifen antagonize estrogen by

A

binding estrogen receptor and preventing recruit hAT co-factor

57
Q

Alzheimers disease is from a

A

misfolded protein

58
Q

chloramphenocol and erythromycin target

A

translation and

peptiyl transferase

59
Q

PCNA

A

acts as a clamp which encircles DNA and binds replisome to affect processive synthesis of DNA

60
Q

high energy compounds

A
  1. PEP
  2. Phosphocreatine
  3. Aceytl Co-A
  4. ATP
61
Q

Chromatin

A
  1. contains 4 different histone proteins with hostine complex
  2. contains fundamental repreating unit= nucleosome
  3. contains linker histone that enables compaction of 10nm fiber to 3nm solenoid
62
Q

post trans mod of proteins

A
  1. methylate lysine
  2. acetylation of lysine
  3. phosphorthrenonine
    4 add sugar to asparagine
63
Q

which domain contains Zn finger structure critical for steroid receptor function

A

DNA binding domain

64
Q

combinational control

A

mechanism involving heterodimeriation fo sequence specific DNA binding proteins that greatly increase number of potential DNA sequences to which proteins can bind and thereby allowing small number of transcription facts to regulate large number of genes.

65
Q

how do activator domains function

A

mediate protein protein interactionsneeded to recruit general transcription machinery

66
Q

how do alkylating agents damage DNA

A

attack nucleophillic groups on bases, leaving adducts

67
Q

function of helix loop helix, bZIP domains serve in transcription factor to

A

mediate bidning transcription factor to specific DNA sequence

68
Q

miRNA and siena are

A

regulatory RNA

69
Q

micheals menton Kcat

A

number of substrate molecules that are converted to product at saturating substrate concentrations

70
Q

chargoff’s rule

A

B form duplex DNA

71
Q

which DNA repair does MutS and MutL proteins serve?

A

mismatch repair

72
Q

deoxyadenosine 5’phosphate is a

A

nucleotide

73
Q

gout

A

purine

uric acid

74
Q

lesch nyhan

A

HPRT1 gene
deficiency of enzyme hypoxanthine
phosphoribisyltransferase 1

high uric acid in body

75
Q

epigenetics

A

covalent methylation of DNA

76
Q

hypermehtylation

A

silencing tumor suppressor gene

77
Q

hypomethylation

A

aberrant transcription oncogenes

78
Q

melanoma

A

thymine dimer

UV light

79
Q

AZT and DDL

A

nucleoside analogue drugs

80
Q

breast/ovarian canver

A

gene: BRCA1/BRCA2
protein: DSB response

81
Q

bloom syndrome and skin cancer predisposition

A

protein: DNA helicase
gene: BLM

82
Q

ataxia telangiextasisia and cancer predisposition

A

gene: ATM
protein: DNA damage checkpoint

83
Q

werner’s syndrome

cancer predisposition

A

gene: WRN

protein: DNA helicase
3’–5’ exonuclease

84
Q

Nijmegan breakage syndrome

A

gene: NBS1

Protein: DSB repair

85
Q

gene: BRCA1/BRCA2

A

breast and ovarian cancer

86
Q

gene: BLM

A

bloom syndrome and skin cancer predisposition

87
Q

gene: ATM

A

atacia telangiectasis and cancer predispostion

88
Q

gene: WRN

A

werner’s syndrome and cancer predisposition

89
Q

gene: NBS 1

A

nijmegan breakage syndrome

cancer predisposition

90
Q

gout caused by

A

purine, uric acid

91
Q

nonpolyposis colorectal cancer is a problem in

A

MMR

92
Q

xerdoerma pigmentosum

A

NER
light sensitivity
abnormal pigmentation

93
Q

cockayne syndrom

A

NER

94
Q

trichothidystrophy

A

NER

95
Q

Marfan syndrom

A

tall and prone to aneurysms

Mutation of fibrillin gene transcript

96
Q

B-thalassemia

A

TATA box

97
Q

Gamma-delta-beta thalassemia

A

deletion in locus control region for the txn of all glob in genes resulting in loss of glob in txn

98
Q

Hemophilia B leyden

A

promotor or clotting protein gene

99
Q

fragile X syndrome

A

expansion of CGG count upstream of FMR1 gene

which causes abnormally high rate of methylation and txn silencing genes

100
Q

craniosynostosis

A

premature closing of sutures in skull

homeodomain

101
Q

waardenburg syndrome

A

white streak in hair
mutation of MIFT
which codes or bHLH

102
Q

androgen insensitivity syndrome

A

zinc fingers

103
Q

leukemia

A

HAT or HDAC

104
Q

Rubinstein Taybi syndrom

A

CREB, CBP (HAT)

105
Q

warfarin

A

anticlotting drug that targets carboxylation of prothrombin

106
Q

cogenitial disorder of glycosylation (CDG)

A

dysfunction of glycosylation mechanism results in CDG

107
Q

prion disease

A

misfolding of proteins

additional beta pleats

108
Q

alzheimers

A

AB-42 accumulation

109
Q

parkinsons

A

beta-synuclein misfiles into lewy bodies

110
Q

alpha amanitin targets

A

inhibits RNA pol II by binding bridge so it can’t translocate
death cap mushrooms

111
Q

rifampicin

A

binds beta subunit of bacterial RNA poly

blocks the exit chamber where assembled RNA exits

112
Q

tamoxifen

A

binds to estrogen receptors as a ligand

prevents estrogen from binding to active site

113
Q

rapamycin

A

phosphorylates 4E-BP so that the initiation complex cannot be formed

114
Q

gleevec

A

cancer treatment competitively inhibits ber-abl kinase

115
Q

antibiotics act to

A

interferes with ribosome (tRNA binding, elongation and peptidyl transferase)

116
Q

velcade

A

inhibits proteosome that degrades good proteins resulting in multiple myeloma