First Aid 54-77 Flashcards
(105 cards)
1
Q
Promoter mutation results in
A
dramatically lower level of gene transcription
2
Q
alpha-amanitin
A
toxin in death cap mushrooms
inhibits RNA Pol II
severe hepatotoxicity
3
Q
MOA Rifampin
A
inhibits RNA Pol in prokaryotes
4
Q
MOA Actinomycin D
A
inhibits RNA Pol in both prokaryotes and eukaryotes
5
Q
What is the function of P bodies
A
in cytoplasm
for quality control
exonucleases, microRNAs, decapping enzymes
can store mRNA there for future use
6
Q
Smith and U1 RNP, whose antibodies are associated with SLE and MCTD, respectively, function normally as
A
part of the spliceosome
7
Q
An example of a condition thought to be due to an abnormal splicing variant
A
beta-thalassemia
8
Q
What end of tRNA binds the aa?
A
3’ CCA
Can Carry Amino acids
9
Q
Function of aminoacyl-tRNA snythetase
A
“matchmaker”
makes sure the right aa is being chosen
1 per aa
uses ATP to charge tRNA
10
Q
A site
A
aminoacyl -tRNA binds to A site
rRNA ribozyme catalyzes peptide bond formation to add polypeptide to aa in A site
11
Q
P site
A
ribosome advances 3 nucleotides toward 3’ end of mRNA, moving peptidyl tRNA to P site (translocation
P site accomodates growing peptide
12
Q
E site
A
holds empty tRNA as it exits
13
Q
Regulatory proteins that control cell cycle events, activate CDKs
A
cyclins
become cyclin-CDK complexes which phosphorylate other proteins to coordinate cell cycle progression
14
Q
function of p21
A
induced by p53
inhibits CDKs –> hypophosphorylation (activation) of Rb
Active Rb binds and inactivated TF EF2 –> inhibition of G1–>S
15
Q
Give two examples of stable cell lines, that can enter G1 from G0 if stimulated
A
Hepatocytes
Lymphocytes
16
Q
Where does N-linked oligosaccharide addition to proteins occur?
A
RER
17
Q
The golgi complex modifies N-oligosaccharides on:
A
asparagiNe
18
Q
The golgi comples modifies O-oligosaccharides on
A
serine and threOnine
19
Q
What does the mannose-6-phosphate tag mean?
A
Trafficking from golgi to lysosomes
20
Q
Defect in I cell disease (aka mucolipidosis type II)
A
defect in N-acetylglucosaminyl-1-phosphotransferase
–> failure of golgi to phosphorylate mannose residues
–> proteins that should be degraded are instead secreted
coarse facial features, restriced joint movement, high plasma levels of lysosomal enzymes
21
Q
COPI
A
vesicular trafficking protein
golgi–golgi
cis-golgi–RER
retrograde
22
Q
COPI II
A
vesicular trafficking protein
ER–cis golgi
anterograde
23
Q
Defects in the ubiquitin-proteasome pathway have been implicated in some cases of
A
Parkinson disease
24
Q
Function of peroxisome
A
catabolism of very long chain FA (through beta-oxidation), branched chain FA, amino acids, ethanol
25
Actin and microvilli are made of
microfilaments
26
vimentin, desmin, cytokeratin, lamins, glial fibrillary acid proteins (GFAPs), neurofilaments
all made of
intermediate filaments
27
Immunohistochemical stain for vimentin (IF) identifies
mesenchymal tissue
ie fibroblasts, endothelial cells, macrophages
sarcomas, RCC, endometrial carcinoma, meningioma
28
Desmin (IF) stains for
muscle
29
Immunohistochemical stain for epithelium
cytokeratin (IF)
30
"Microtubules Get Constructed Very Poorly"
```
Drugs that act on Microtubules
Mebendazole (antihelminth)
Griseofulvin (antifungal)
Colchicine (antigout)
Vincristine/Vinblastine (anticancer)
Paclitaxel (anticancer)
```
31
Defect in primary ciliary dyskinesia
aka Kartagener syndrome
dynein arm defect --> immotile cilia
bronchiectasis, recurrent sinusitis, ectopic pregnancy, infertility
32
Where does ouabain bind?
K+ site (extracellular)
| inhibits Na/K ATPase
33
Digoxin directly inhibits
Na/K ATPase --> indirect inhibition of the Na/Ca exchange --> Ca increased --> cardiac contractility increased
34
Type I collagen, where is it found besides bone?
```
skin
tendon
dentin
fascia
cornea
late wound repair
```
35
The vitreous body contains what kind of collagen?
type II
36
Collagen type found in:
reticulin
skin, blood vessels, uterus, fetal tissue, granulation tissue
type III
| defective in *vascular* type of Ehlers-Danlos (3-ED)
37
type IV collagen found where?
BM, basal lamina, lens
defective in Alport syndrome
targeted by autoantibodies in Goodpasture syndrome
38
Collagen is 1/3 made of
glycine
| Gly-X-Y-Gly-X-Y...
39
Problems forming the triple helix in collagen synthesis (glycosylation step)
Osteogenesis imperfecta
40
Diseases with problems collagen cross-linking
Menkes disease
| Ehlers-Danlos
41
Gene defects in COL1A1 and COL1A2
Osteogenesis imperfecta
| most common type is AD with reduced production of normal type I collagen
42
X-linked recessive disease
impaired Copper absorption and transport
defective ATP7A gene
Menkes disease
reduced activity of lysyl oxidase
kinky, brittle hair, growth retardation, hypotonia
43
Complications seen in Ehlers-Danlos
organ rupture
berry and aortic aneurysms
joint dislocation
44
connections between vertebrae are called
ligamenta flava
45
Why use a Northern blot?
Useful for studying mRNA levels which reflect gene expression
46
Test that identifies DNA-binding proteins ie TFs using labeled oligonucleotide probes
Southwestern blot
47
How is a CD4 count performed?
Flow cytometry
48
Immunologic test to detect either specific antigen or antibody in a patient's blood sample
ELISA
49
Test used for specific localization of genes and direct visualization of chromosomal anomalies at the molecular level, ie microdeletions, duplications, translocations
FISH
50
Phenotype varies among individuals with the same genotype
Variable expressivity
51
Not all individuals with a mutant genotype show the mutant phenotype
Incomplete penetrance
52
One gene contributes to multiple phenotypic effects
```
Pleiotropy
ie PKU (light skin, intellectual disability, musty body odor)
```
53
A heterozygote produced a nonfunctional protein that inhibits the normal gene product from functioning
Dominant negative mutation
54
An example of mosaicism
McCune-Albright syndrome
defective G-protein signaling
unilateral cafe-au-lait spots, precocious puberty, polyostotic fibrous dysplasia, multiple endocrine abnormalities
55
Mutations at different loci can produce a similar phenotype
Locus heterogeneity
| ie albinism
56
Different mutations at the same locus produce a similar phenotype
Allelic heterogeneity
| ie beta-thalassemia
57
Presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrially inherited disease
Heteroplasmy
58
An individual can inherit an AR disorder from one parent through
Uniparental disomy
59
Explain p^2 + 2pq + q^2 = 1
```
p^2 = frequency of homozygosity for allele p
q^2 = frequency of homozygosity for allele q
2pq = frequency of heterozygotes
p+q = 1
```
60
Using Hardy-Weinberg, the frequency of an X linked recessive disease in males and females is:
```
q = males
q^2 = females
```
61
How does imprinting work in Prader-Willi syndrome?
Gene from mom silent, gene from dad is mutated or deleted
or
No genes from dad, both from mom maternally imprinted (uniparental disomy)
**opposite for Angelman syndrome, but both on chrom 15
62
In AD diseases, with one heterozygous parent, about how many children affected?
1/2
63
X-linked recessive means
Sons of heterozygous mothers have a 50% chance of being affected;
skips generations;
no male-->male inheritance possible
64
X-linked dominant means
transmitted through both parents
dad transmits to all daughters but no sons
mom transmits to half of her children
65
```
Alport syndrome
fragile X syndrome
Rett syndrome
hypophosphatemic rickets
all what inheritance?
```
X-linked (dominant)
66
X-linked
increased phosphate wasting in PCT
rickets-like presentation
hypophosphatemic rickets
67
Muscl biopsy showing ragged red fibers
MELAS syndrome - Mitochondrial encephalopathy, lactic acidosis, stroke-like episodes
failure in oxidative phosphorylation
mitochondrial inheritance
68
Mutation in fibroblast growth factor receptor 3
Achondroplasia
Inhibits chondrocyte proliferation
most common cause of dwarfism
AD
69
PKD2
chromosome 4
second most common mutation in Autosomal dominant polycystic kidney disease
AD
70
5 letters on polyp, think
FAP
chrom 5
progresses to colon cancer if colon not resected
AD
71
Autosomal dominant disorder to blood vessels
```
Heredity hemorrhagic telangectasia aka Osler-Weber-Rendu
recurrent episxtaxis
skin discolorations
AV malformations
GI bleeds
Hematuria
```
72
severe atherosclerotic disease early in life
corneal arcus
tendon xanthomas
mutation in or absence of:
LDL receptor
Familial hypercholesterolemia
AD
73
Inheritance of hereditary spherocytosis
AD
74
Caudate atrophy in HD (chrom 4) results in what changes to these chemicals:
dopamine
GABA
ACh
dopamine up
GABA down
ACh down
AD
75
SBLA cancer syndrome aka
Li Fraumeni syndrome
TP53 abnormalities
sarcoma, breast, leukemia, adrenal gland
AD
76
Fibrillin is the scaffold for
Elastin
chrom 15
Marfan syndrome
AD
77
MEN 2A and 2B are associated with the RET proto-oncogene whereas MEN 1 is associated with
MEN1 gene
| AD
78
juvenile cataracts
meningiomas
ependymomas
what syndrome?
Neurofibromatosis type 2
also acoustic schwannomas
NF2 gene on chrom 22
AD
79
syndrome with optic gliomas and pheochromocytomas
```
Neurofibromatosis type 1
Lisch nodules
cafe-au-lait spots
cutaneous neurofibromas
NF1 gene on chrom 17
```
80
What test screens newborns for CF?
Trypsinogen screening
81
What CF pattern is seen on CXR?
Reticulonodular pattern
82
How is infertility in men conferred in CF?
Absence of vas deferens
83
"Oblivious Females Will Often Give Her Boys Her x-Linked Disorders"
```
Ornithine transcarbamylase deficiency
Fabry disease
Wiskott-Aldrich syndrome
Ocular albinism
G6PD deficiency
Hunter syndrome
Bruton agammaglobulinemia
Hemophilia A and B
Lesch-Nyhan sndrome
Duchenne (and Becker) MD
```
84
Pseudohypertrophy of calf muscles in MD due to
fibrofatty replacement of muscle
85
Function of dystrophin
Anchoring or muscle fibers
frameshift mutation most common
***non-frameshift --> Becker
86
AD
CTG trinucleotide repeat expansion in DMPK gene
symptoms?
Myotonic type 1 MD
cataracts, muscle wasting, frontal balding, testicular atrophy, arrhthmia
"My Tonia, My testicles, My Toupee, My Ticker"
87
Trinucleotide repeat results in hypermethylation of FMR1 gene --> gene inactivation
symptoms?
Fragile X syndrome
2nd most common genetic intellectual disability after Down syndrome
macroorchidism, long face, large jaw, large ears, MVP, autism
88
Trinucleotide expansion of CAG
Huntington disease
89
Trinucleotide expansion of CTG
Myotonic dystrophy
90
Trinucleotide expansion of GAA
Friederich ataxia (chrom 9)
91
gap between 1st two toes
duodenal atresia
Brushfield spots
Down syndrome
chrom 21 codes for APP
increased risk for ALL and AML
meiotic I nondisjunction most common cause
92
Ist trimester ultrasound shows increased nuchal translucency, hypoplastic nasal bone
Down syndrome
PAPP-A down
free beta HCG up
93
Second trimester quad screen shows increased inhibin A, decreased estriol
Down syndrome
94
First trimester shows low PAPP-A and beta-HCG
Both Edwards syndrome (trisomy 18) and Patau syndrome (trisomy 13)
95
```
cleft lip/palate
rocker bottom feet
holoprosenecephaly
congenital HD
cutis aplasia
micropthalmia
microcephaly
```
Patau syndrome
| trisomy 13
96
```
rocker bottom feet
prominent occiput
clenched hands and overlapping fingers
congenital heart disease
rocker bottom feet
small jaw (micrognathia)
```
Edwards syndrome
| trisomy 18
97
Mineral oil intake can cause
fat soluble vitamin deficiencies
98
Pantothenic Acid, used in the body as
| comes from
Vitamin B5
| CoA
99
Biotin, aka
Vitamin B7
100
Folate, aka
Vitamin B9
| stored in liver for 3-4 months
101
Pseudotumor cerebri - vitamin cause
Vitamin A excess
102
Bitot spots on conjunctiva (white plaques)
| Immunosuppression
Vitamin A deficiency
103
How to diagnose Beriberi
increase in RBC transketolase (HMP Shunt) activity following B1 administration
104
```
Pyruvate dehydrogenase (link between glycolysis and TCA);
alpha-ketoglutarate dehydrogenase (TCA);
Transketolase (HMP Shunt);
Branched chain ketoacid dehydrogenase
All require:
```
```
TPP Cofactor
From thiamine (B1)
```
105
Confusion
Ophthalmoplegia
Ataxia
damage to what part of the brain?
Common triad of Wernicke-Korsakoff
mamillary bodies, medial dorsal nucleus of thalamus
