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First Aid - Biochem 1
Terms in this set (100)
template cytosine and adenine
these are methylated during DNA replication to distinguish old from new strands
this relaxes DNA coiling allowing for transcription
A and G ; C, T, U
these are purine NT ; these are pyrimidines
deamination of this NT makes uracil
thymine ; guanine
this NT has a methyl group ; this purine has a ketone
glycine, aspartate, glutamine
these amino acids are necessary for purine synthesis
aspartate, carbamoyl phosphate
components needed to make pyrimidines
PRPP (sugar and phosphate) ; 6 mercaptopurine
starting point for de novo purine synthesis ; what inhibits this?
Ribose 5P -> PRPP -> IMP -> AMP and GMP
steps in purine synthesis
Carbamoyl phosphate --> orotic acid (temporary base) + PRPP -> UMP -> UDP -> CTP and dUDP -> dUMP -> dTMP
steps in pyrimidine synthesis
pyrimidine synthesis and urea cycle ; ornithine transcarbamoylase
2 cycles that use carbamoyl phosphate ; what enzyme will cause build up of it if deficient?
this inhibits ribonucleatide reductase (in pyrimidine synthesis)
inhibition thymidylate synthase -> decreased dTMP
effect of 5-FU on pyrimidine synthesis
dihydrofolate reductase (reduced dTMP)
what does methotrexate inhibit?
UMP synthase ; can't convert orotic acid to UMP
this is defective in orotic acuduria ; what is effect?
orotic acid in urine (w/o hyperammonemia), megaloblastic anemia, failure to thrive ; oral uridine
findings in orotic aciduria (UMP synthase defect) ; what is treatment?
excess ATP and dATP -> inhibition ribonucleotide reductase -> decreased DNA synthesis -> decreased lymphocyte count (SCID)
effect of adenosine deaminase deficiency
HGPRT deficiency -> poor purine salvage -> excess uric acid production ; XR
pathogenesis of Lesch-Nyhan syndrome ; what is inheritance?
retardation, self-mutlization, aggression, hyperuricemia, gout, choreoathetosis
findings in lesch-nyhan syndrome
xanthine -> uric acid
last reaction in purine salvage pathway
GMP and IMP
what accumulates in Lesch-Nyhan syndrome?
AUG ; UGG
codon for methionine ; codon for tryptophan (only 2 with only 1 codon...rest are redundant)
DNA polymerase 3
this initiates replication on RNA primer -> elongates leading strand by adding dNT to 3' end, also has 3'-5' exonuclease activity
DNA polymerase 1
this degrades RNA primer and replaces with DNA (prokaryotes only), has 5'-3; exonoculease
this kind of DNA repair is mutated in HNPCC
nonhomoglous end joining of ds
this is mutated in ataxia telangiectasia
mRNA start codon
UGA, UAA, UAG
these are mRNA stop codons
RNA polymerase I ; RNA pol II ; RNA pol III
this makes rRNA (most abundant form of RNA) ; this makes mRNA (longest) ; this makes tRNA (smallest)
RNA polymerase II ; a-amanitin (Amanita phalloides)
this opens DNA at the promoter site ; what inhibits this (causes severe hepatotoxicity if ingested)?
patients with this condition make Ab to spliceosomal snRNPs
segment/coding at 3' end of tRNA that binds amino acids
this antibiotic binds 30s subunit and blocks attachment of aa-tRNA
this antibiotic binds 50S and inhibits peptidyl transferase
these antibiotics bind 50S and prevent release of uncharged tRNA after it has given its amino acid
these antibiotics bind 30S and inhibit formation of initiation complex and cause misreading of mRNA
p53 and Rb
these normally inhibit G1 to S progression
these are RER in neurons -> synthesize enzymes and peptide NT
steroid synthesis and detoxification of drugs and poisons
what occurs at smooth ER?
this is added to proteins by golgi apparatus for trafficking to lysosomes
vesicular trafficking protein for retrograde golgi to golgi, and golgi to ER
vesicular trafficking protein for anterograde golgi to golgi, and ER to golgi
vesicular trafficking protein for trans Golgi to lysoomes, and plasma membrane to endosomes
protein responsible for retrograde transport on microtubule (+ -> -)
protein responsible for anterograde transport on microtubule (- -> +)
mutation in lysosomal trafficking regulator gene (needed for MT dependent sorting of endosomal proteins into late multi vesicular endosomes)
what is defect in Chediak Higashi syndrome?
recurrent pyogenic infections, partial albinism, peripheral neuropathy (mutation in LYST gene so multivesicular endosomes can't form)
clinical presentation of Chediak Higashi syndrome
dynein arm defect -> immotile cilia
what is defect in Kartagener's syndrome?
male infertility, decreased female fertility, bronchiectasis, recurrent sinusitis, a/w situs inversus
clinical presentation of Kartagener's syndrome
these are cytoskeletal elements for structure -> vimentin, desmin, lamina, GFAP, neurofilaments
this is immunohistochemical stain for CT
this inhibits Na/K pump by binding to K site
collagen in bone, skin, tendon, cornea, late wound repair
collagen in cartilage, hyaline, vitreous body, nucleus pulposus
collagen type in reticulin -> skin, blood vessels, uterus, fetal tissue, granulation tissue -> defective in Ehlers Danlos
type 4 ; Alport syndrome
collagen type in basement membrane or basal lamina ; what disease has defect in this collagen?
where does hydroxylation and glycosylation of collagen occur?
glycosylation (can't form triple helix)
osteogenesis imperfecta has problem with this step of collagen synthesis
cleavage of disulfide-rich terminal regions of pro collagen transform it into this
cross-linking (can't cross link)
Ehlers Danlos has problem with this step of collagen synthesis
Cu containing lysyl oxidase
this is responsible for reinforcement of staggered tropocollagen molecules by covalent lysine-hydroxyllysine cross-links
XR ; progressive hereditary nephritis and deafness, ocular disturbances
inheritance of Alport Syndrome ; what is clinical presentation?
this is defective Marfan's syndrome
agarose gel electrophoresis
this is used to separate size of PCR products
RNA (study mRNA levels)
what does Northern blot analyze?
what does Southern blot analyze? (uses radio labeled probe to anneal and visualize)
in this test, sample protein separated via gel electrophoresis -> transferred to filter and labeled Ab is used to bind relevant protein
DNA binding proteins
this test identifies DNA binding proteins
what is the test: nucleic acid sequences arranged in grid, DNA or RNA probe hybridized, scanner detects relative amounts of complementary binding
this is used to test antigen-Ab reactivity -> if Ab (indirect) or Antigen (direct) are in the patients serum, will have colorful positive reaction
this test is used for specific localization of genes and direct visualization of anomalies at molecular level via RNA or DNA probes
cells in the body differ in genetic makeup due to post fertilization loss or change of genetic information during mitosis
presence of both normal and mutated mtDNA -> variable expression in mitochondrial inherited disease
error occurs here in heterozygous UPD
meiosis II (postzygotic chromosomal duplication of one pair, loss of original)
error occurs here in homozygous UPD
q ; q^2
frequency of XR disease in males ; in females
p ; 2p
frequency of XD disease in males ; in females
paternal imprinting chromosome 15 or UPD
genetic defect in Prader Willi syndrome -> MR, hyperphagia, obesity, hypogonadism, hypotonia
maternal imprinting chromosome 15 or UPD
genetic defect in Angelman's syndrome -> MR, seizures, ataxia, inappropriate laughter
inheritance for hypophosphatemic (vitamin D resistant) rickets -> increased phosphate wasting at proximal tubule, decreased bone mineralization
ragged red fibers
muscle biopsy findings in mitochondrial myopathies -> mutations affecting mitochondrial function
what is defective in achondroplasia?
chromosome 16 - PDK1 gene
what is mutated in ADPKD -> a/w polycystic liver disease, berry aneurysms, MVP
chromosome 5 - APC gene
what is mutated in FAP (auto dominant)?
what is defective/deficient in familial hypercholesterolemia (auto dominant)?
telangiectasia, recurrent epistaxis, skin discoloration, AVM
findings in hereditary hemorrhagic telangiectasia -> AD condition
inheritance for hereditary spherocytosis -> spectrin or ankyrin defect, elevated MCHC, hemolytic anemia
decreased GABA and ACH
NT change in Huntington's disease
cystic medial necrosis of aorta
this causes aortic incompetence and dissecting aortic aneurysm in marfan's syndrome (FPN1 mutation)
mutated gene in MEN 2A and 2B (AD)
chromosome that contains NF1 gene -> causes NF type 1 (AD)
chromosome that contains NF2 gene -> bilateral acoustic schwannoma, juvenile cataracts (AD)
inheritance for tuberous sclerosis -> facial lesions, hypopigmented ash leaf spots, cortical/retinal hamartomas, renal cysts, cardiac rhabdomyomas
chromosome 3 - deletion VHL tumor suppressor -> HIF (TF) constitutive activation and angiogenic GF activation
genetic defect of von Hippel Lindau disease -> hemangioblastoma or retina/cerebellum/medulla, bilateral renal carcinoma
chromosome 7 - CFTR gene Phe deletion (inability to secrete Cl into secretions)
what is defective in cystic fibrosis
this is treatment option for cystic fibrosis -> loosens mucous plugs by cleaving disulfide bonds w/in mucous glycoproteins
inheritance for Bruton's agammaglobulinemia, Wiskott-Aldrich syndrome and Fabry's disease
inheritance for G6PD deficiency, ocular albinism, and Lesch Nyhan syndrome
inheritance for DMD, Hunter's syndrome, hemophilia A and B, ornithine transcarbamoylase
X linked frameshift mutation -> dystrophin gene deletion
pathogenesis of DMD
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