Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Step 1 > Behavioral science, biostats, biochem, genetics > Flashcards

Behavioral science, biostats, biochem, genetics Flashcards

1
Q

MoA of MTX, TMP, and pyramethamine?

A

Inhibit dihydrofolate reductase (can’t convert DHT back to THF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Drug w/MoA similar to mycophenolate?

A

Ribavirin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cause of Lesch-Nyhan syndrome?

A

Defective purine salvage due to absent HGPRT (converts hypoxanthine to IMP and guanine to GMP).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q 
Sx of Lesch-Nyhan?
H
G
P
R
T
A 
H = hyperuricemia
G = gout
P = pissed off (aggression, self-mutilation)
R = retardation
T = dysTonia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Lesch-Nyhan: inheritance?

A

X-linked recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name an antibiotic category that’s a topoisomerase II & IV inhibitor in prokaryotes.

Name an anti-neoplastic agent that is the same for eukaryotic cells.

A

Fluoroquinolones

Etoposide/tenoposide (“topo”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What disease has defective nucleotide excision repair?

A

Xeroderma pigmentosa (prevents repair of pyrimidine dimers due to UV light exposure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When does NER occur?

A

G1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When does base excision repair occur?

A

Throughout cell cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What disease has defective mismatch repair?

A

Lynch syndrome (HNPCC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When does MMR occur?

A

G2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Fanconi anemia and ataxia-telangiectasia are both eg’s of diseases where what is mutated?

A

Nonhomologous end-joining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What anti-biotic inhibits RNA poly in prokaryotes?

What anti-neoplastic can do it in eukaryotes (+ prokaryotes)?

A

Rifampin

Actinomycin D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are anti-Smith AB’s targeting?

What dz are they specific for?

A

snRNP’s (small nuclear ribonucleoproteins)

SLE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do snRNP’s do?

A

Combine w/primary transcript (forms spliceosome), looping occurs, and intron is excised (exons are joined together)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What sequence is found at the acceptor stem of tRNAs?

A

CAA

“can carry aa’s”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Explain the cascade of events starting at p53 and ending in inhibition of the cell cycle.

A
  1. p53 induces p21, which inhibits CDKs, leading to hypo-P’lation of Rb
  2. Hypo-P’lated Rb binds to and inactivates E2F (ts factor), leading to inhibition of G1-S phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Name some ‘permanent’ cell types that only regenerate from stem cells.

Name some “stable” (quiescent) cells that can enter G0 from G1 when stimulated.

A
  • Neurons, skeletal + cardiac muscle, RBCs

- Hepatocytes, lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the name of rER in neurons?

A

Nissl bodies (synthesize peptide NT’s for secretion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What types of cells are rich in sER?

What types of cells are rich in rER?

A

Any cells that produce steroid hormones or participate in drug/poison detox (eg adrenal cells or hepatocytes)

Cells that export/secrete lots of stuff (eg goblet cells or plasma cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What’s the cellular marker for trafficking to the lysosome?

A

Mannose-6-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the name of the disease where the golgi can’t P’late mannose and proteins are sent out of the cell rather than being degraded by lysosome?

A

I-cell disease (inclusion cell disease/mucolipidosis type II)

[typical features- course facial features, clouded corneas, restricted joint movement. Fatal usually in chidlhood.]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What ribonucleoprotein traffics proteins from ribosome to rER?

A

Signal recognition peptide (SRP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What protein coats endosomes and transports from rER to golgi?

Golgi to rER (retrograde)?

What processes does clathrin participate in?

A

COPII

COPI

Clathrin:
Trans-golgi to lysosomes.
PM to endosomes (eg LDLR reuptake)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Defects in the proteosome have been implicated in some forms of what disease?

A

Parkinson disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does vimentin stain? (intermediate filament)

A

Mesenchymal tissue (eg fibroblasts, endothelial cells, macrophages)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does desMin stain? (intermediate filament)

A

Muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does cytokeratin stain? (intermediate filament)

A

Epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does Gfap stain? (intermediate filament)

A

NeuroGlia (eg astrocytes, schwann cells, oligodendroglia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does neurofilament stain? (intermediate filament)

A

Neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Name the drugs that act on microtubules? (what is mnemonic?)

A

“MT’s Get Constructed Very Poorly”

Mebendazole (antihelminthic)
Griseofulvin (antifungal)
Colchicine (antigout)
Vincristine/Vinblastine (antineoplastic)
Paclitaxel (antineoplastic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What cardiac drug inhibits the NKP?

A 
Cardiac glycosides (digoxin & digitoxin)
- Leads to indirect inhibition of Na/Ca exchange, leading to increased intracellular Ca and increased contractility!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

(What plan-derived toxin binds to the NKP at the K+ site to inhibit it?)

A

(Ouabain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where are the 4 types of cartilage found?

recall mnemonic

A

“Be (so totally) Cool, Read Books”

bONE, (skin, tendon): type I
CarTWOlage: type II
Reticulin, blood vessels: type III
BM: type IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which collagen is defective in osteogenesis imperfecta type 1?

A

Type I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Which collagen is defective in the rare vascular form of Ehler-Danlos syndrome?

(Classical Ehlers-Danlos?)

A

Type III

Type V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What type of collagen is defective in Alport syndrome and targeted by AB’s in Goodpasture syndrome?

A

Type IV (BM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What step in collagen synthesis is required for procollagen formation?

A

Glycosylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Which part of collagen synthesis are Ehlers-Danlos and Menkes disease a/w?

A

Crosslinking (final step in ECF) of tropocollagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Which part of collagen synthesis is osteogenesis imperfecta a/w?

A

Glycosylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What genes are most commonly mutated in osteogenesis imperfecta?

A

COL1A1 and COL1A2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Menkes disease: inheritance pattern?
Pathophys?
Gene mutation?
Sx?

A
  • X-linked recessive
  • Imparied Cu absoprtion/xport
  • ATP7A (Menkes protein) -> decreased lysyl oxidase
  • Brittle, kinky hair; hypotonia, growth retardation
43
Q

What enzyme can break down elastase?

A

Alpha1-antitrypsin

44
Q

Name the glycoprotein that forms a sheeth around elastin.

A

Fibrillin (mutated in Marfan)

45
Q

McCune-Albright syndrome:
Cause?
Sx?
Lethal if?…

A
  • Due to mutation in G-protein signalling
  • Sx: cafe-au-lait spots, polyostotic fibrous dysplasia, precocious puberty, multiple endocrine abnormalities
  • Lethal if mutation occurs before fertilization (affecting all cell), but survivable if mosaicism
46
Q

What is heteroplasmy?

A

Presence of both nl and mutated mtDNA, resulting in variable expression of mitochondrially inherited disease.

47
Q

Rett syndrome, fragile X syndrome, and alport syndrome are all eg’s of what inheritance pattern?

A

X-linked dominant

48
Q

What is MELAS syndrome?

Inheritance pattern?

A

M E mitochondrial encephalopathy
L A lactic acidosis
S stroke-like episodes

Mitochondrial inheritance

(ragged red fibers on muscle bx)

49
Q

Gene mutated in achondroplasia?

A

FGFR3 (inhibits chondrocyte proliferation)

50
Q

Gene mutated in FAP?

A

APC

51
Q

Gene mutated in familial hypercholesterolemia?

A

LDLR

52
Q

Generally, hereditary hemorrhagic telangiectasia is a d/o of ____________.

A

Blood vessels.

53
Q

Gene mutated in Li-Fraumeni?

Nickname?

A

(T)P53

SBLA: sarcoma, breast, leukemia, adrenal

54
Q

What is a common deletion seen in CF? (AR)

A

Phe508

55
Q

What test is diagnostic for CF?

A

Increased Cl- in the sweat

56
Q

Name the X-linked recessive d/o’s.

“Oblivious Females Will Often Give Her Boys Her x-Linked Disorders”

A

“Oblivious Females Will Often Give Her Boys Her x-Linked Disorders”

OTC deficiency
Fabry disease
Wiskott-Aldrich syndrome
Ocular albinism
G6PD deficiency
Hunter syndrome
Bruton agammaglobulinemia
Hemophilia A & B
Lesch-Nyhan syndrome
Duchenne (& Becker) muscular dystrophy
57
Q

What type of mutation is Duchenne muscular dystrophy due to?

A

Frameshift (Beck is non-frameshift)

58
Q

What’s the mnemonic to remember the sx of myotonic dystrophy type 1? (AD)

A 
My Tonia (myotonia)
My Testicles (atrophy)
My Toupee (frontal balding)
My Ticker (arrhythmia)
59
Q

What are the repeats in the NT expansion diseases?

A

Huntington: CAG
Fragile X: CGG
Friedrich ataxia: GAA
Myotonic dystrophy: CTG

60
Q

How could you distinguish Edwards from Patau?

A

Edwards: low set Ears
Patau: cleft liP/Palate, holoProsencephaly, Polydactyly

61
Q

What does Cri-du-chat mean?

Other sx?

A

“Cry of the cat”

Microcephaly, retardation, epicanthal folds, VSD

62
Q

DiGeorge and velocardiofacial syndromes (22q11 microdeletion) are due to aberrant development of the _____________________.

A

3rd & 4th branchial pouches

63
Q

What is the name of the following B vitamins?

B1, B2, B3, B5, B6, B7, B9, B12

A 
B1 = thiamine
B2 = Riboflavin
B3 = Niacin
B5 = pantothenic acid ("pento"thenic acid)
B6 = Pyridoxine
B7 = biotin
B9 = folate
B12 = cobalamin
64
Q

What enzyme links glycoslysis to the TCA cycle?

A

Pyruvate DH

65
Q

What reactions is thiamine (B1) important for?

think “ATP”

A

Alpha-ketoglutarate DH
Transketolase
Pyruvate DH

Ber1 Ber1

66
Q

What are the 2 C’s of B2 deficiency?

A
  • Cheilosis (inflammation of the lips, scaling and fissures at corner of mouth)
  • Corneal vascularization
67
Q

What are the 3 D’s of B3 def?

A
  • Diarrhea
  • Dementia
  • Dermatitis (Casal’s necklace)
68
Q

How is folate (B9) obtained in the diet?

A

“Fol”iage (green, leafy vegis)

69
Q

What is the main symptom caused by folate def? (B9)

A

Megaloblastic anemia (no neuro sx)

70
Q

Which vitamin def. can cause subacute combined degeneration?

A

B12 (cobalamin)

Also can cause megaloblastic anemia like B9.

71
Q

Sx of Zn def?

A
  • Delayed wound healing
  • Hypogonadism
  • Decreased adult hair
  • Dysgeusia/anosmia
  • Acrodermatitis enteropathica
72
Q

What is marasmus?

A

Total calorie malnutrition

“Marasmus results in Muscle wasting”

73
Q

Besides edema, why can you get a fatty liver in Kwashiorkor (protein malnutrition)?

A

Decreased apolipoprotein synthesis

you also get anemia

74
Q

___________ causes glycolysis to produce zero net ATP (vs. 2).

A

Arsenic

[Arsenic inhibits lipoic acid (TCA), causing vomiting, rice water stools, garlic breath.]

75
Q

What is the function of the pyruvate DH complex?

Name the 5 required cofactors.

A

Links glycolysis w/TCA cycle (pyruvate -> acetyl-CoA)

B1-B5 + lipoic acid (there’s no B4)

76
Q

In pyruvate DH complex deficiency (X-linked), where are the 2 places that excess pyruvate gets shunted?

A
  • To lactate (via LDH)

- To Alanine (via ALT)

77
Q

What are the onLy pureLy ketogenic AA’s? (used to treat pyruvate DH complex def.)

A

Lysine

Leucine

78
Q

In what cell types is pyruvate conversion to lactate (cori cycle) used predominantly instead of TCA cycle? (via LDH)

A

Anaerobic glycolysis:

  • RBCs
  • WBCs
  • Kidney medulla
  • Lens
  • Cornea
  • Testes
79
Q

What inhibits complex I of ETC?

A

Rotenone (rotenONE)

80
Q

What inhibits complex III of ETC?

A

Antimycin A (an-3-mycin A)

81
Q

What inhibits complex IV of ETC?

A

CO/CN (4 letters)

  • This step converts 1/2 O2 + 2H+ to water, so makes sense that these could bind
82
Q

What inhibits the ATP synthase of the ETC?

A

Oligomycin

83
Q

List 3 agents that can uncouple the ETC.

A
  • 2,4-dinitrophenol (weight loss)
  • Aspirin (fever s/p ASA OD)
  • Thermogenin in brown fat (produces heat)
84
Q

What is the reason we have the pentose phosphate pw? (HMP shunt?)

A

Provides source of NADPH (eg for glutathione reduction in RBCs, FA/chol biosynthesis for steroids…). Also yields ribose for NT synthesis and glycolytic intermediates.

Sites: lactating mammary glands, liver, adrenal cortex, RBCs

85
Q

What is the rate-limiting enzyme of the PPP (HMP shunt)?

Deficiency causes what disease?

A

*Glucose-6-phosphate DH (most common enzyme def. in humans!)

This is why you get Heinz bodies in G6PD def.–denatured Hgb ppt’s w/in RBCs due to oxidative stress since PPP is defunct, can’t reduce glutathione to protect RBCs.

86
Q

What enzyme is absent in galactosemia, leading to the toxic buildup of galactitol?

A

Galactose-1-phosphate uridyltransferase

87
Q

In what inborn error of metabolism would you smell a musty body odor?

A

PKU (Pee-(K)-yew)
+ Retardation
+ Fair skin

Phe hydroxylase def.

88
Q

What 3 AA’s build up in maple syrup urine disease?

A

“I Love Vermont” maple syrup
Isoleucine
Leucine
Valine

(branched)

89
Q

While the lens is subluxated upwards in Marfan, in what disease would it be downwards?

A

Homocystinuria (cystathione synthase def.)
+ Homocysteine in urine
+ Retardation
+ Osteoporosis
+ *Marfanoid habitus
+ Kyphosis
+ Thrombosis, atherosclerosis (stroke, MI)

90
Q

What do cystine stones appear like?

What other protein’s are also lost in the urine? (COLA)

A

Hexagonal

COLA: cystine, ornithine, lysine, arginine

91
Q

Tx for cystine stones?

What test is diagnostic?

A
  • Urinary alkalinization + chelation (eg penicillamine), hydration
  • Urinary cyanide-nitroprusside test
92
Q

What are the 2 major pw’s inhibited in Von Gierke disease?

A

GNG & glycogenolysis

def. glucose-6-phosphatase

93
Q

Where does FA synthesis generally occur? (3)

A

Liver
Lactating mammary glands
Adipose tissue

94
Q

What shuttle brings citrate into the mito for FA synthesis?

What shuttle brings fatty acyl-CoA out of the mito for energy use?

A

Citrate shuttle

Carnitine shuttle

95
Q

Where is lipoprotein lipase (LPL) found, and what does it do?

A

Vascular endothelial surface

Degrades TG’s circulating in chylomicrons & VLDLs

96
Q

Hormone-sensitive lipase degrades TGs stored in _______________.

A

Adipocytes

97
Q

What does LCAT do?

A

Catalyzes esterification of cholesterol

98
Q

What does apolipoprotein A-I do?

A

Activates LCAT

chylomicrons, HDLs

99
Q

What does apolipoprotein C-II do?

A

LPL cofactor

chylomicrons, HDLs, VLDLs

100
Q

What does apolipoprotein E do?

A

Mediates remnant uptake

All except LDLs

101
Q

What does apolipoprotein B-48 do?

A

Mediates chylomicron secretion

chylomicrons, remnants

102
Q

What does apolipoprotein B-100 do?

A

Binds LDLR

VLDLs, IDLs, LDLs

103
Q

What are the familial dyslipidemias type I, IIa, and IV?

A

I = hyper-chylomicronemia (AR; LPL or apo-CII def.)

II = familial hypercholesterolemia (AD; LDLR problem)

IV = hyper-triglyceridemia (AD; overproduction of VLDLs)

Step 1 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions