Biochem: molecular/cellular bio, genetics

Question 1

uracil is made from deamination of

Answer 1

cytosine

Question 2

cytosine deamination yields

Answer 2

uracil

Question 3

leflunomide MOA

Answer 3

blocks dihydroorotate dehydrogenase to prevent conversion of carbamoyl phosphate to orotic acid

Question 4

hydroxyurea MOA

Answer 4

inhibits ribonucleotide reductase to prevent conversion of UDP to dUDP

Question 5

substances from glutamine + CO2 to synthesis of CTP

Answer 5

carbamoyl phosphate, orotic acid, UMP, UDP, CTP

Question 6

substances from glutamine + CO2 to synthesis of dTMP

Answer 6

carbamoyl phosphate, orotic acid, UMP, UDP, dUDP, dUMP, dTMP

Question 7

MTX, TMP, and pyrimethamine block

Answer 7

dihydrofolate reductase, which normally recycles DHF into THF

Question 8

5FU blocks

Answer 8

thymidylate synthase, which normally converts dUMP to dTMP

Note: the active form of 5FU is 5FdUMP

Question 9

azathioprine/6MP MOA

Answer 9

impairs purine synthesis by blocking formation of IMP from PRPP

Question 10

Mycophenolate and ribavirin MOA

Answer 10

blocks IMP dehydrogenase to prevent conversion of IMP to GMP

Question 11

probenecid MOA

Answer 11

stimulates conversionof uric acid to urine

Question 12

Lesch-Nyhan (deficiency, symptoms)

Answer 12

HGPRT: hyperuicemia, gout, pissed off, retardation, dystonia

Question 13

this sugar unbinds the repressor on lac operon

Answer 13

high lactose

Question 14

XP is caused by a defect in

Answer 14

NER, which removes oligonucleotides e.g. pyrimidine dimers

Question 15

Spontaneous deamination is repaired by

Answer 15

BER. AP endonuclease cleaves 5’ end, lyase cleaves 3’ end

Question 16

Ataxia telangiectasia and Fanconi anemia have a defect in this DNA repair mechanism

Answer 16

NHEJ

Question 17

function of eukaryotic RNA pol I

Answer 17

rRNA

Question 18

function of eukaryotic RNA pol II

Answer 18

mRNA

Question 19

function of eukaryotic RNA pol III

Answer 19

tRNA

Question 20

what are the functions of the T arm and D arm of tRNA?

Answer 20

ribosome binding; aminoacyl-tRNA synthase recognition

Question 21

Defect in I-cell disease

Answer 21

failure to add mannose-6-P (defect in n-acetylglucosaminyl-1-phosphotransferase)

Question 22

Sx of I-cell disease

Answer 22

coarse facies, clouded corneas, restricted joint movement, high plasma level of lysosomal enzymes

Question 23

this protein is involved in retrograde vesicular trafficking

Answer 23

COP I

Question 24

this protein is involved in anterograde vesicular trafficking

Answer 24

COP II

Question 25

this protein is involved in transport between Golgi and lysosomes, and in receptor mediated endocytosis

Answer 25

Clathrin

Question 26

stain for mesenchymal intermediate filaments

Answer 26

vimentin

Question 27

this microtuble motor protein does anterograde transport (toward positive end)

Answer 27

kinesin

Question 28

this microtubule motor protein does retrograde transport (toward negative end)

Answer 28

dynein

Question 29

ouabin MOA

Answer 29

inhibits Na/K ATPase by binding to K+ site

Question 30

classical Ehlers-Danlos is a deficiency in this collagen

Answer 30

type V

Question 31

Menkes (deficiency, consequence, sx)

Answer 31

``` defective ATP7A (Menkes protein), which absorbs and transports copper Problems with cross-linking tropocollagen into collagen (copper needed for lysl oxidase) Sx: brittle, kinky hair; growth retardation; hypotonia ```

Question 32

McCune-Albright syndrome (def, manifestations)

Answer 32

mutation in G-protein signaling. Survivable only if mosaic | Unilateral cafe-au-lait, polyostotic fibrous dysplasia, precocious puberty, multiple endocrine abnormalities

Question 33

which gene is mutated/deleted in Prader-Willi

Answer 33

paternal gene defect | with maternal imprinting

Question 34

which gene is mutated/deleted in AngelMan

Answer 34

maternal gene defect | with paternal imprinting

Question 35

inheritance type Osler-Weber-Rendu

Answer 35

AD

Question 36

chr for Huntington

Answer 36

chr 4 | "Hunting 4 CAGs"

Question 37

chr for AD PKD

Answer 37

MCC PKD1 on chr 16. PKD1 on chr 4

Question 38

chr for Marfan

Answer 38

FBN1 on chr 15

Question 39

chr for NF1

Answer 39

aka von Recklinghausen disease. chr 17

Question 40

chr for NF2

Answer 40

chr 22

Question 41

chr for VHL

Answer 41

chr 3

Question 42

chr for CF

Answer 42

chr 7. often deletion of Phe508

Question 43

Inheritance ornithine transcarbamylase deficiency

Answer 43

XR | "Oblivious Female Will Often Give Her Boys Her x-Linked Disorders"

Question 44

inheritance Fabry disease

Answer 44

XR. The one sphingolipidosis that isn't AR | "Oblivious Female Will Often Give Her Boys Her x-Linked Disorders"

Question 45

inheritance WAS

Answer 45

XR ("Oblivious Female Will Often Give Her Boys Her x-Linked Disorders")

Question 46

inheritance ocular albinism

Answer 46

XR ("Oblivious Female Will Often Give Her Boys Her x-Linked Disorders")

Question 47

inheritance G6PD def

Answer 47

XR ("Oblivious Female Will Often Give Her Boys Her x-Linked Disorders")

Question 48

inheritance hereditary spherocytosis

Answer 48

AD

Question 49

inheritance mucopolysaccharidoses (except Hunter)

Answer 49

AR

Question 50

inheritance Wilson disease

Answer 50

AR

Question 51

inheritance thalassemias

Answer 51

AR

Question 52

inheritance glycogen storage diseases

Answer 52

AR

Question 53

inheritance Kartagener

Answer 53

AR

Question 54

inheritance myotonic dystrophy type 1

Answer 54

AD

Question 55

manifestations of myotonic dystrophy type 1

Answer 55

testicular atrophy, frontal balding, arrhythmia | "My Testicles, My Toupee, My Ticker"

Question 56

repeat for Fragile X

Answer 56

CGG

Question 57

repeat for Friedreich Ataxia

Answer 57

GAA

Question 58

repeat for Huntington

Answer 58

CAG

Question 59

repeat for myotonic dystrophy

Answer 59

CTG

Question 60

lab findings down syndrome

Answer 60

1st trimester: low PAPP-A, high b-hCG | 2nd: HIGH b-hCG, low AFP, HIGH inhibin A, low estriol

Question 61

lab findings Edwards

Answer 61

(trisomy 18) | low PAPP-A, LOW b-hCG, low AFP, low/normal inhibin A

Question 62

lab findings Patau

Answer 62

(trisomy 13) | low PAPP-A, LOW b-hCG

Question 63

chr for FAP

Answer 63

5

Question 64

chr for cri-du-chat

Answer 64

5

Question 65

chr for HFE

Answer 65

6

Question 66

chr for Williams

Answer 66

7, long arm deletion

Question 67

chr for Friedreich Ataxia

Answer 67

9

Question 68

chr for Wilms tumor

Answer 68

11

Question 69

chr for beta globin gene

Answer 69

11

Question 70

chr for RB1

Answer 70

13

Question 71

chr for BRCA2

Answer 71

13

Question 72

chr for alpha globin

Answer 72

16

Question 73

chr for BRCA1

Answer 73

17