First Aid Biochem

Front 1

Which histone is not found in the nucleosome core?

Back 1

H1

Front 2

Which amino acids are required for purine synthesis?

Back 2

Glycine, aspartate, glutamine

Front 3

What is the MOA of Hydroxyurea?

Back 3

Inhibits ribonucleotide reductase

Front 4

What is the MOA of 6-mercaptopurine?

Back 4

Blocks de novo purine synthesis

Front 5

What is the MOA of 5-fluorouracil?

Back 5

Inhibits thymidylate synthase --> decreased dTMP

Front 6

What is the MOA of methotrexate?

Back 6

Inhibits dihydrofolate reductase --> decreased dTMP

Front 7

What is the MOA of trimethoprim?

Back 7

Inhibits bac dihydrofolate reductase --> decreased dTMP

Front 8

Which amino acids are required for pyrimidine synthesis?

Back 8

Aspartate

Front 9

Which nucleotide builds up in SCID?

Back 9

ATP

Front 10

Which purine salvage enzyme is absent in Lesch-Nyhan syndrome?

Back 10

HGPRT

Front 11

What is the MOA of FQs?

Back 11

inhibits prokaryotic topoisomerase II & IV --> prevents DNA replication

Front 12

In which direction are DNA and RNA synthesized?

Back 12

5' --> 3'

Front 13

Which method of DNA repair is mutated in xeroderma pigmentosum?

Back 13

Nucleotide excision repair

Front 14

Which method of DNA repair is mutated in heriditary nonpolyposis colorectal cancer?

Back 14

Mismatch repair

Front 15

Which amino acid is coded by the start codon?

Back 15

AUG (GUG) codes for methionine

Front 16

Which RNA polymerase makes tRNA?

Back 16

RNA polymerase III

Front 17

Does polyadenalation occur on the 5' or 3' end?

Back 17

3'

Front 18

__________ contain actual genetic information, and _________ are the intervening noncoding segments of DNA

Back 18

Exons; Introns

Front 19

What enzyme charges tRNA?

Back 19

aminoacyl-tRNA synthetase

Front 20

Which phase of the cell cycle is inhibited by p53 and Rb?

Back 20

G1 - S

Front 21

Which anti-cancer drugs act on microtubules?

Back 21

Vincristine and Vinblastine prevent microtubule formation

Paclitaxel prevents microtubule breakdown

Front 22

Which anti-fungal drug acts on microtubules?

Back 22

Griseofulvin blocks formation

Front 23

Which antihelminthic drugs act on microtubules?

Back 23

mebendazole and thiabendazole block microtubule formation

Front 24

What is the MOA and clinical use of colchicine?

Back 24

Blocks microtubule formation and used in Rx of gout?

Front 25

What is the pathogenesis of Chediak-Higashi syndrome?

Back 25

microtubule formation defect --> decreased fusion of phagosomes and lysosomes --> recurrent pyogenic infections

Front 26

What is the pathogenesis of Kartagener's syndrome?

Back 26

immotile cilia due to dynein arm defect --> infertility and recurrent sinusitis

Front 27

Which vitamin is required for the hydroxylation of collagen?

Back 27

vit C (def --> scurvy)

Front 28

What is the pathogenesis of Alport syndrome?

Back 28

defect in Type IV collagen --> defective basement membrane in eyes, ears and glomeruli --> occular disturbance, deafness and nephritis

Front 29

Which blotting procedures are used for DNA, RNA and proteins?

Back 29

SNoW DRoP : Southern = DNA, Northern = RNA, Western = Protein

Front 30

What is the equation for Hardy-Weinberg equilibrium?

Back 30

p^2 + 2pq + q^2 = 1

Front 31

Define imprinting

Back 31

One allele is innactivated by methylation --> reliance on uniparental allele expression

Front 32

What is the inheritance pattern of hypophosphatemic rickets?

Back 32

X-linked Dominant

Front 33

What chromosome is affected in William's syndrome?

Back 33

microdeletion on 7q

Front 34

Which embryologic structures are affected in 22q11 deletions?

Back 34

3rd and 4th branchial pouches --> cleft palate, abnormal facies, thymic aplasia, cardiac defects, hypocalcemia

Front 35

Name the B vitamins

Back 35

B1 = thiamine
B2 = riboflavin
B3 = niacin
B5 = pantothenic acid
B6 = pyridoxine
B12 = cobalamin

Front 36

What are the effects of vit A def?

Back 36

Night blindness, dry skin

Front 37

What are the effects of vit B1 def?

Back 37

(thiamine) decreased TPP --> decreased decarboxylation rxns --> impaired glucose breakdown --> ATP depletion

Front 38

What are the effects of vit B2 def?

Back 38

(riboflavin) oxidation/reduction cofactor --> cheilosis and corneal vascularization

Front 39

What are the effects of vit B3 def?

Back 39

(niacin) deacreased NAD --> glossitis, diarrhea, dermatitis, dementia, death

Front 40

vit B5 is an essential component of what cofactor?

Back 40

CoA

Front 41

What are the effects of vit B12 def?

Back 41

Macrocytic megaloblastic anemia w/ neurologic symptoms

Front 42

Which vit is required for the conversion of CH3THF --> THF?

Back 42

B12 (cobalamin)

Front 43

What is the function of S-adenosyl-methionine?

Back 43

SAM steals all the meth

Front 44

What is the function of Biotin?

Back 44

cofactor for carboxylation enzymes

Front 45

Ingestion of raw eggs may cause what vit deficiency?

Back 45

biotin

Front 46

What are the clinical signs of zinc deficiency?

Back 46

delayed wound healing, hypogonadism, decreased pubic hair, distorted taste and smell

Front 47

What is the limiting reagent for alcohol metabolism?

Back 47

NAD+

Front 48

What is the rate-determining enzyme of Glycolysis?

Back 48

PFK-1

Front 49

What is the rate-determining enzyme of gluconeogenesis?

Back 49

Fructose-1,6-bisphosphate

Front 50

What is the rate-determining enzyme of TCA cycle?

Back 50

Isocitrate dehydrogenase

Front 51

What is the rate-determining enzyme of Glycogen synthesis?

Back 51

Glycogen synthase

Front 52

What is the rate-determining enzyme of glycogenolysis?

Back 52

Glycogen phosphorylase?

Front 53

What is the rate-determining enzyme of the HMP shunt?

Back 53

G6PD

Front 54

What is the rate-determining enzyme of de novo pyrimidine synthesis?

Back 54

Carbamoyl phosphate synthetase II

Front 55

What is the rate-determining enzyme of de novo purine synthesis

Back 55

Glutamine-PRPP amidotransferase

Front 56

What is the rate-determining enzyme of the Urea cycle?

Back 56

Carbamoyl phosphate synthetase I

Front 57

What is the rate-determining enzyme of fatty acid synthesis?

Back 57

Acetyl-CoA carboxylase

Front 58

What is the rate-determining enzyme of fatty acid oxidation?

Back 58

Carnitine acyltransferase I

Front 59

What is the rate-determining enzyme of ketogenesis?

Back 59

HMG-CoA synthase

Front 60

What is the rate-determining enzyme of cholesterol synthesis?

Back 60

HMG-CoA reductase

Front 61

Which enzyme converts Glucose to Glucose-6-phosphate?

Back 61

Hexokinase

Front 62

What do all the mono-saccharides become to enter the glycolysis chain?

Back 62

Glyceraldehyde-3-P

Front 63

Which steps of Glycolysis require ATP?

Back 63

Glucose --> Glucose-6-phosphate

Fructose-6-P --> Fructose-1,6-BP

Front 64

Which enzyme converts glucose --> Glucose-6-phosphate?

Back 64

glucokinase

Front 65

Does fructose-2,6-bisphosphate stimulate or inhibit glycolysis?

Back 65

Stimulate

Front 66

What are the only purely ketogenic AAs?

Back 66

Lysine and Leucine

Front 67

What is the Rx for pyruvate dehydrogenase deficiency?

Back 67

increased intake of ketogenic nutrients (eg high fat, increased lysine and leucine)

Front 68

Which cofactors are required for pyruvate dehydrogenase complex and alpha-ketoglutarate dehydrogenase complex?

Back 68

B1, B2, B3, B5, lipoic acid

Front 69

What is the metabolic effect of von Gierke's dz

Back 69

Glucose-6-phosphatase def --> no gluconeogenesis

Front 70

___-chain fatty acids cannot produce new glucose

Back 70

Even

Front 71

Deficiency of what enzyme --> chronic granulomatous dz?

Back 71

NADPH oxidase

Front 72

Pts with chronic granulomatous disease are at increased risk of infection from what type of bac?

Back 72

cat-positive (they neutralize their own H202)

Front 73

What is the inheritance pattern of G6PD def?

Back 73

X-linked recessive

Front 74

What will you see on blood smear of pt w/ G6PD?

Back 74

Heinz bodies and bite cells (oxidized hemoglobin in RBCs and phagocytic bite marks from cleanup)

Front 75

Which enzyme is defective in essential fructosuria?

Back 75

fructokinase

Front 76

Which enzyme is defective in fructose intolerance?

Back 76

aldolase B

Front 77

What accumulates in fructose intolerance?

Back 77

Fructose-1-P

Front 78

Which enzyme is absent in classic galactosemia?

Back 78

galactose-1-P uridyltransferase

Front 79

Which enzyme converts Glucose to sorbitol?

Back 79

aldose reductase

Front 80

Which tissues have both aldose reductase and sorbitol dehydrogenase?

Back 80

liver, ovaries, seminal vesicles

Front 81

What is the most common urea cycle disorder?

Back 81

Ornithine transcarbamoylase def (XR) --> orotic acid in blood and urine, decreased BUN, hyperammonemia

Front 82

What is the treatment for PKU?

Back 82

eliminate phenylalanine from diet and increase tyrosine in diet

Front 83

Which enzyme is deficient in alkaptonuria and what are the clinical findings?

Back 83

deficiency of homogentisic acid oxidase

findings = brown pigmented sclera, black pee

Front 84

Which vit is required for conversion of homocysteine to methionine?

Back 84

B12 (cobalamin)

Front 85

Which vit is required for conversion of homocysteine to cystathionine?

Back 85

B6 (pyridoxine)

Front 86

Which amino acids build up in maple syrup urine disease?

Back 86

branched chain amino acids (Ile, Leu, Val) --> severe CNS defects, death

Front 87

Does glucagon lead to phosphorylation or dephosphorylation of glycogen phosphorylase?

Back 87

phosphorylation

Front 88

Which lysosomal storage diseases have increased incidence in Ashkenazi Jews?

Back 88

Tay-Sachs, Niemann-Pick, Gaucher's

Front 89

What are the two Mucopolysaccharidoses Lysosomal Storage diseases?

Back 89

Hurler's and Hunter's (accumulate Heparan sulfate and dermatan sulfate)

Front 90

What are the two XR lysosomal storage diseases?

Back 90

Fabry's and Hunter's

Front 91

What is the most common lysosomal storage dz?

Back 91

Gaucher's dz

Front 92

What is the def enzyme in Fabry's dz?

Back 92

alpha-galactosidase A

Front 93

What is the def enzyme in Gaucher's dz

Back 93

glucocerebrosidase

Front 94

What is the def enzyme in Niemann-Pick dz?

Back 94

sphingomyelinase

Front 95

What is the def enzyme in Tay-Sachs dz?

Back 95

hexosaminidase A

Front 96

What is the def enzyme in Krabbe's dz?

Back 96

galactocerebrosidase

Front 97

What is the def enzyme in Metachromatic leukodystrophy?

Back 97

arylsulfatase A

Front 98

What is the def enzyme in Hurler's syndrome?

Back 98

alpha-L-iduronidase

Front 99

What is the def enzyme in Hunter's syndrome?

Back 99

iduronate sulfatase

Front 100

What clinical sign differentiates Niemann-Pick from Tay-Sachs?

Back 100

Niemann-Pick --> hepatosplenomegaly

Tay-Sachs --> no hepatosplenomegaly

Front 101

What clinically distinguishes Hunter's from Hurler's?

Back 101

Hunter's has aggressive behavior and no corneal clouding

Front 102

How many kcal in 1g of protein?

Back 102

4

Front 103

How many kcal in 1g carbs?

Back 103

4

Front 104

How many kcal in 1g fat?

Back 104

9

Front 105

How long do you have to be exercising before FA oxidation becomes your main source of fuel?

Back 105

hours

Front 106

How long do you have to be starving before adipose stores become your main source of energy?

Back 106

3 days

Front 107

How long does it take glycogen stores to be depleted?

Back 107

~1 day

Front 108

Which apolipoprotein binds LDL receptors?

Back 108

B-100

Front 109

Which apolipoprotein mediates remnant uptake?

Back 109

E

Front 110

Which apolipoprotein activates LCAT?

Back 110

A-I

Front 111

Which apolipoprotein is a lipoprotein lipase cofactor?

Back 111

C-II

Front 112

Which apolipoprotein mediates chylomicron secretion?

Back 112

B-48

Front 113

Which lipoprotein is increased in type I dyslipidemia?

Back 113

hyperchilomicronemia

Front 114

Which lipoprotein is increased in type IIa dyslipidemia?

Back 114

familial hypercholesterolemia --> LDL

Front 115

Which lipoprotein is increased in type IV dyslipidemia?

Back 115

hypertriglyceridemia

Front 116

What is abetalipoproteinemia?

Back 116

Hereditary inability to synthesize lipoproteins due to def in Apo B-100 and Apo B-48 (AR)