cellular biochem and genetics Flashcards Preview

Step I > cellular biochem and genetics > Flashcards

Flashcards in cellular biochem and genetics Deck (111):
1

M phase

mitosis and cytokinesis
shortest phase

2

CDK

constitutive
inactive

3

cyclins

phase specific
activate CDKs

4

cyclin-CDK complex

phosphorylate other proteins to coordinate cell cycle progression
must be activated and inactivated at appropriate times for cell cycle to progress

5

tumor supressors

p53
hyophosphorylated Rb
inhibit G1 -> S progression
mutated -> LiFraumeni syndrome

6

permanent cells

remain in G0
regenerate from stem cells
neurons, skeletal and cardiac mm
RBCs

7

stable/quiescent cells

enter G1 when stimulated
hepatocytes
lymphocytes

8

labile cells

never go to G0
divide rapdily w/short G1
most affected by chemo
skin, hair, bone marrow, GI lining, germ cells

9

RER

synthesis of secretory proteins
Nissl bodeis (RER in neurons) synthesis NTs
mucus-secreting goblet cells and AB secreting plasma cells have a lot

10

Free ribosomes

cytosolic and organellar proteins

11

SER

site of steroid synthesis and detox of drugs and poisons
lack surface ribosomes
liver hepatocytes and steroid hormone producing cells

12

signal recognition particle (SRP)

abundant, cytosolic ribonucleoprotein that traffics proteins from the ribosome to the RER
if absent proteins accumulate in cytosole

13

vesicular trafficking proteins

COPI, COPII, Clathrin

14

COPI

golgi -> golgi (retrograde)
cisGolgi -> ER

15

COPII

ER -> cisGolgi (anterograde)

16

clathrin

transGolgi -> lysosomes
plasma membrane -> endosomes

17

peroxisome

catabolism of very long chain fatty acids
brr-chain fatty acids
aa

18

proteasome

barrel-shaped protein complex, degrades damaged or ubiquinated proteins
defects implicated in parkinsons

19

I-cell disease

inclusion cell disease
inherited lysosomal storage disorder
defect in N-acetylglucosaminyl-1-phosphotransferase -> failure of goligi to phosphorylate mannose -> proteins excreted extraceullularly rather then into lysosomes

20

clinical features of I-cell disease

coarse facial features
clouded corneas
restricted joint mvmt
high plasma levels of lysosomal enzymes
often fatal in childhood

21

microfiiliments

mm crontraction
cytokinesis
actin

22

intermediate filaments

cell structure
vimentin
desmin
cytokeratin
lamins
GFAP
neurofilaments

23

microtubules

mvmt, cell division
cilia
flagella
mitotic spindle
axonal trafficking
centrioles

24

vimentin stain

CT

25

desMin stain

mm

26

cytokeratin

epi

27

GFAP

neuroGlia

28

neurofiliaments

neurons

29

microtubules anatomy

polymerized heterodimers of alpha and beta tubulin
each dimer has 2 GTP bound

30

dynein

retrograde (+ -> -)

31

kinesin

anterograde (- -> +)

32

drugs that act on microtubules

Microtubules Get Constructed Very Poorly
Mebendazole (anithelminthie)
Griseofulvin (antifungal)
Colchicine (antigout)
Vincristine/Vinblastine (antiCA)
Paclitaxel (antiCA)

33

Cilia structure

9+2 arrangement of microtubule droplets

34

kartagener syndrom

aka primary ciliary dyskinesia
immotile cilia d/t dynein arm defect
male and female infertility
increased risk for ectopic
brochiectasis, recurrent sinusitis
situs inversus
ADPCKD

35

oubain

inhbits NA/K ATPase by binding K site

36

cardiac glycosies

digoxin/digitoxin
directly inhibit Na/K ATPase -> indirect inhbition of Na/Ca exchange -> increased Ca -> increased contractility

37

Collagen

Be So Totally Cool, Read Books
I- Bone, skin, tendon (late wound repair)
II- Cartilage (vitreous body, nucleus propulsus)
III- Reticulin, skin, blood vessels, granulation tissue
IV- BM, basal lamina, lens (type IV under the floor-BM)

38

decreased type I collagen production

osteogenesis imperfecta type I

39

vascular type of Ethers Danlos

uncommon
type III deficient

40

alport syndrome

type IV defective

41

collagen synthesis inside fibroblast

synthesis in RER -> preprocollagen
hydroxylation in RER (requires Vit C)
glycosylation in RER -> precollagen (osteogenesis imperfecta)
exocytosis

42

collagen synthesis outside fibroblast

proteolytic- cleavage of disulfide rich terminal regions -> tropocollagen
cross linking -> requires Cu (Menkes disease, ED)

43

osteogenesis imperfecta

brittle bone disease
most common AD
decreased production of normal type I collagen
fracture, blue sclera, hearing loss, fental imperfections

44

Ethers Danlos

AD or AR
associated w/joint dislocaton, berry/aortic aneurysms, organ rupture

45

types of ED

-hypermobility type, most common, joint instability
-classical type mutation in type V collagen, joint and skin
-vascular type deficient type III collagen, vascular and organ rupture

46

menkes disease

XR
impaired Cu absorption and transport
defective menkes protein (ATP7A)
decreased lysyl oxidase activity
brittle, kinky hair, growth retardation, hypotonia

47

Elastin

rick in nonhydroxylated proline, glycine, and lysine
broken down by elastase which is normally inhibited by alpha 1 anti-trypsin

48

marfans

misfolded fibrillin-1
glycoprotein that forms sheath around elastin

49

Blotting procedures

SNoW DRoP
Southern = DNA
Northern = RNA
Western = protein

50

locus heterogenity

mutations at different loci can produce same phenotype
albinism

51

allelic heterogenity

different mutations in same locus produce same phenotype
beta thalassemia

52

heteroplasmy

presence of both normal and mutated mtDNA
variable expression in mitochondrially inherited diseases

53

prader-willi

maternal imprinting (moms usually silent) Paternal deleted
hyperphagia, obesity, retardation. hypogonadism, and hypotonia
25% d/t maternal uniparental disomy

54

angleman

paternal impriting (dads usually silent) maternal deleted
inappropriate laughter, seizures, ataxia, severe intellecutual disability
5% d/t paternal uniparental disomy

55

mitochondrial myopathies

rare disorder often presents w/myopathy, lactic acidosis, and CNS disease
secondary to failure in ox phos
mm Bx- ragged red fibers

56

ADPKD

85% d/t mutation in PKD1, chrom 16 (16 letters in polycystic kidney)
15% d/t mutation in PKD2 (chrom 4)

57

familial adenomatous polyposis inheritance?

AD

58

familial hypercholesterolemia inheritance?

AD

59

albinism inheritance?

AR

60

hereditary hemorrhagic telangiectasia inheritance?

AD

61

cystic fibrosis inheritance?

AR

62

glycogen storage diseases inheritance?

AR

63

hemochromatosis inheritance?

AR

64

hereditary sphrocytosis inheritance?

AD

65

Huntingtons inheritance?

AD

66

Kartagener syndrome inheritance?

AR

67

LiFraumeni syndrome inheritance?

AD

68

Marfan's syndrome inheritance?

AD

69

multiple endocrine neoplasia (MEN) inheritance?

AD

70

NF1 inheritance?

AD

71

mucopolusaccharidoses inheritance?

AR

72

phenylketonuria inheritance?

AR

73

NF2 inheritance?

AD

74

sickle cell inheritance?

AR

75

sphingolipidoses inheritance?

AR (except Fabry's)

76

Tuberous sclerosis inheritance?

AD

77

thalasemias inheritance?

AR

78

VHL disease inheritance?

AD

79

Wilson's disease inheritance?

AR

80

Familial adenomatous polyposis

AD
colon becomes covered w/adenomatous polyps after puberty
progresses to colon CA unless colon resected
mutations on chrom 5 (5 letters in polyp) APC gene

81

familial hypercholesterolemia

AD
elevated LDL d/t defective or absent LDL Rs
tendon xanthomas (classically in achilles), corneal arcus

82

hereditary hemorrhagic telangiectadsia

AD
aka Osler-Weber-Rendu sndrome
telangiectasia, epistaxis, skin disocoloration, AVMs, GI bleds, hematuria

83

hereditary spheocytsis

AD
spheroid RBCs, d/t spectin or ankyrin defect
hemolytic ane ia
increased MCHC, RDW
Tx splenectomy

84

huntingtons

AD
increased DA, decreased GABA and ACh
gene on chrom 4 (hunting For 4 food)
CAG repeats, anticipation

85

Li-Fraumeni syndrome

AD
mutated TP53 -> multiple CAs at young age
aka SBLA CA syndrome b/c get sarcomas, breast, leukemia, and adrenal gland CA)

86

Marfan's

AD
FBN1 gene mutation on chrom 15 -> defective fibrillin-1 (scaffold for elastin)
tall w/long extremities, pectus excavatum, hypermobile joints, arachnodactyl
cystic medial necrosis of aorta -> aortic aneurysm
Floppy mitral valve
subluxation of lenses

87

MEN 1

AD
pancreatic (gastinomas, insulinomas)
pituitary
parathyroid
MEN1 gene

88

MEN 2A

AD
parathyroid
pheochromocytoma
thyroid
RET gene

89

MEN 2B

AD
pheochromocytoma
thyroid
mucosal neuromas
marfanoid body habitus
RET gene

90

NF1

AD, 100% penetrance, variable expression
aka von Recklinghausen
cafe-au-laits spots
cutaneous neurofibromas
optic gliomas
pherochromocytomas
Lisch nodules (pigmented iris hamartomas)
NF1 gene on chrom 17 (17 letters in von Recklinghausen)

91

NF2

AD
b/l acoustic schwannomas
juvenile cataracts
mengingiomas
ependymomas
NF2 gene on chrom 22

92

Tuberous sclerosis

Dx Triad:
-Angiofibromas on face
-Metal delays
-Seizures
a lot get cardiac rhadomyomas
TSC1- hamertin
TSC2- tuberin
Ash leaf patch-shine woodslamp (UVA) -> fluoresces
AD, incomplete penetrance, variable expression

93

VHL

numerous tumors, both benign and malignant
deletion of VHL gene on chrom 3

94

CF

CFTR on chrom 7
most common mutation -> misfolded protein -> decreased CL and H20 secretion
N-acetylcystein loosen mucus plugs

95

x-linked recessive disorders

Be Wise Fool's GOLD Heeds Silly HOpe
Bruton agammaglobulinemia
Wischott-aldrich syndrome
Fabry's
G6PD deficiency
Ocular albinism
Lesch-Nyhan syndrome
Duchenne and becker mm dystrophy
Hunter Syndrome
Hemophillia A and B
Ornithine transcarbamylase deficieny

96

Duchenne

x-linked d/t frameshift
truncated dystrophin
weakness begins in pelvic girdle mm and progresses superiorly
psuedohypertrophy of calf mm d/t fibrofatty replacement of mm
Gower maneuver to stand
waddling gait
onset

97

Becker

x-linked d/t non-frameshift insertions
partially functional
less severe then duchennes
onset in adolescene or early adulthood

98

mytonic mm dystrophy type 1

AD
CTG repeat in DMPK gene
myotonia, mm wasting, cataracts, testicular atrophy, frontal balding, arrhythmia
My Tonia, My Testicles, My Toupee, My Ticker

99

Fragile X-syndrome

x-linked, CGG repeat
affecting methylation and expression of FMR1 gene
2nd MCC of genetic intellectual disability (downs first)
post-pubertal macroorchidism
long face w/large jaw
large ecerted ears
autism
MV prolapse
Fragile X = eXtra large testes, jaw, and ears

100

trinucleotide repeat expansions

Try hunting for my fried eggs (X)
huntingtons
myotonic dystropy
friedreich ataxia
fragile X syndrome

101

down syndrome associations

gap btwn 1st 2 toes
duodenal atresia
hirschsprugs
congenital heart disease (ASD)
Brushfield spots
early onset alxhemiers
ALL and AML

102

down syndrome 1st trimester ultrasound

increased nuchal translucency and hypoplastic nasal bone
serum PAPP-A is decreased
free B-hCG increased

103

down syndrome 2nd trimester quad screen

decreaed alpha-fetoprotein
increased beta-hCG
decreased estriol
increased inhibin A

104

Edwards syndrome

trisomy 18
severe intellectual disability
rocker-bottom feet
low-set ears
celnced hands w/overlapping fingers
prominent occiput
congenital heart disease
death w/in 1 yr

105

edwards 1st triemster

PAPP-A and free beta-hCG decreased

106

edwards quad screen

decreased alpha-fetoprotein
decreased beta-hCG
decreased estriol
decreased or normal inhibin A

107

Patau syndrome

severe intellectual disability
rocker bottom feet
microphthalmia
microencephaly
cleft lip/palate
holoprosencephaly
polydactyly
congenital heart disease
cutis aplasia
death w/in 1 yr

108

patau first trimester

decreased beta-hCG
decreased PAPP-A
increased nuchal translucency

109

Cri-du-Chat syndrome

congenital microdeletion of short arm of chrom 5 microcephaly
moderate to severe intellectual disabiliyt
high pitched crying/mewing
epicanthal folds
VSD

110

williams syndrome

microdeletion of long arm of chrom 7
distinctive elfin facies
intellectual disability
hypercalcemia
well developed verbal skills, extreme friendliness w/strangers
CV problems

111

DiGeorge

22q11 deletions
CATCH-22
Cleft palate
abnormal facies
thymic aplasia
cleft palate
hypocalcemia (secondary to parathyroid aplasia)
velocardiofacial syndrome- only palate, facial, and cardiac