Biochemistry Flashcards
amanita phalloides - death cap mushroom - toxin - alpha-amanitin - causes death via?
inhibition of RNA polymerase - hepatotoxic
Does poly A-polymerase require a template?
No! recognizes AAUAAA polyadenylation signal
What are P bodies
these function as quality control of mRNA in the cytoplasm
they have the following function
exonuclease
decapping (7-methyl guanosine cap)
and micro-RNAs
mRNA can also be stored in them for future use?
what is anti-smith?
anti snRNP antibody highly specific for lupus
what is anti-U1 RNP
anti snRNP antibody found in mixed connective tissue disease (MCTD)
3’ end of tRNA
CCA - can carry aminos :)
Nissle bodies
RER in neurons that synthesize NTs for release
who is rich in RER
Goblet cells - mucin
plasma cells - ab
who is rich in SmoothER
Steroid producing cells - adrenal cortex / gonads
detoxifying (drugs and poisons) - hepatocytes
COP-I
retrograde
cis golgi to ER
COP-II
anterograde
ER to cis golgi
Clathrin
trans golgi -to lysosome
or
endocytosis to lysosome (receptor mediated endo - e.g. LDL)
If we stain for vimentin, what are we looking for?
connective tissue
if we stain for desmin what are we looking fot?
muscle
if we stain for cytokeratin, what are we looking for?
epithelial
if we stain for neurofilaments what are we looking for?
neurons
if we stain for GFAP what are we looking for?
neuroglia
glial fibrillary acid protein
kinesin -
anterograde to microtubule
dynein
retrograde to microtubule
5 drugs that act on microtubules?
mebendazole (antihelminthe) griseofulvin (antifungal) colchicine (antigout) vincristine (anticancer) / vinblastine paclitaxel (anticancer)
Menkes disease
X linked
copper absorption error from Menkes protein (ATP7A)
copper necessary cofactor of lysyl oxidase in collagen triple helix crosslinking –> brittle hair / growth retardation / hypotonia
Loss of heterozygosity - disease example
Retinoblastoma - if a patient inherits or develops a mutation in a tumor suppressor gene, the complementary allele must be deleted/mutated before cancer develops. this is not true of oncogenes
McCune Albright syndrome is an example of
mosaicism - confers survivability mutation effect g-protein signaling unilateral cafe o lait polyostotic fibrous dysplasia precocious puberty multiple endocrine abnormalities
locus heterogeneity
different loci can produce similar phenotype - albinism
allelic heterogeneity
different mutations in the same loci produce same phenotype - beta thalassemia
what could you think of (other than infidelity) if someone is manifesting a autosomal recessive trait if only one parent is a carrier?
uniparental disomy
example of x-linked dominant disorder
hypophosphatemic rickets -
wasting of phosphate of PCT
Li Fraumeni
p53
SBLA
Sarcoma; Breast; Leukemia; Adrenal
effect on aorta in marfan
cystic media necrosis
MEN1
MEN gene
pancreas
parathyroid
pituitary
MEN2a
RET
Thyroid (medullary)
Phen
Parathyroid
MEN2b
RET
Thyroid (medullary)
Phen
Marfanoid
what is randomly associated with risk of thymoma?
myasthenia gravis
which cancer is lambert eaton associated wtih
small cell lung
endrophonium test?
AChE inhibitor test for Myasthenia gravis vs. Lambert Eaton
MG should improve
cool way to test for thiamine deficiency
RBC increase in transketolase activity post thiamine administration
CFTR gene location
7
why do males with CF have infertility
absent vas deferens
what is given to CF patients to loosen mucus plugs
N-acetylcysteine - cleaves disulfide bonds
what is myotonic dystrophy?
autosomal dominant mutation CTG trinucleotide repeat expansion in DMPK gene leads to abnormal expression of myotonin protein kinase, this leads to: myotonia muscle wasting cataracts testicular atrophy frontal balding arrhythmia my toupe my ticker my testicles myotonia!
Fragile x
X linked trinucleotide repeat CCG FMR1 gene Extra large testes, jaws, ears intellectual mitral valve prolapse
Friedrich ataxia! did you know what kind of mutation this is?
trinucleotide repeat expansion - i did not know this!
Down syndrome common cardiac anomaly
ASD
First trimester screen US
down syndrome findings (2) and serum findings (2)
nuchal translucency
hypoplastic nasal bone
PAPP-A down
free beta-hCG up
Second trimester down syndrome screening (quad)
AFP down
b-hCG up
estriol - down
inhibin A up
AFP and estriol down
b-HCG and inhibinA up
when looking at differences in the prenatal screen of trisomy 21 vs 18
whats different?
In Edwards everything is down first trimester PAPP down bHCG down second trimester inhibinA down AFP down bHCG down estriol down
contrast with Downs first trimester bHCG is up second trimester bHCG and inhibinA up
Patau findings (13x3)
holoprosencephaly (one hemisphere) micropthalmia cleft lip/palate polydactyly heart cutis aplasia
trinucleotide repeat disorders
huntingtons - cag (4)
friedrich ataxia - cgg (9)
myotonic dystrophy - ctg (19)
fragile x - gaa
antidote for methanol or ethylene glycol poisoning
fomepizole - Alochol dehydrogenase inhibitor
ant-abuse
disulfram - inhibits acetylaldehide dehydrogenase
Due to defective myelin synthesis, deficiency in this vitamin can lead to subacute combined degeneration?
Usually vitamin B12
but can also be E
(DC / LCS / SC)
What is elevated in B12 deficiency ?
The substrates of the enzymes it is cofactor for…
Homocysteine (needed to convert methionine)
Methylmalonic acid (needed to convert methylmalonyl-CoA to Succinyl-CoA -used in TCA and myelin synthesis)
ursodeoxycholic acid
bile salt
