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106 Cards in this Set
- Front
- Back
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Hypermethylation of DNA results in...
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Inactivation of DNA transcription
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Histone acetylation results in...
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Relaxation of DNA coiling, making DNA active for transcription.
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Amino acids necessary for purine synthesis...
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Glycine, Aspartate, Glutamine
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Amino acids necessary for pyramidine synthesis...
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Aspartate
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What distinguishes between OTC deficiency and Orotic aciduria?
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Both have elevated orotic acid levels; OTC (urea cycle defect) also has elevated ammonium, where Orotic aciduria (defect in pyrimidine synthesis) does not
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Adenosine deaminase deficiency causes...
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Major cause of SCID; Defect in DNA synthesis causes ATP/dATP excess, imbalancing the nucleotide pool
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Lesch-Nyhan syndrome is caused by what defect? Excess of what product?
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X-linked recessive HGPRT deficiency; overproduction of urate causes hyperuricemia and gout
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Defect in Ataxia-Telangiectasia...
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ATM gene defect causes disfunction of Nonhomologous end joining DNA repair
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Triad of Ataxia-Telangiectasia...
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1. Cerebellar defect - ataxia
2. Spider angiomas - telangiectasia 3. IgA deficiency |
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What molecular change is common to most chain-terminating DNA blockers?
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3'-OH modification, preventing 5' triphosphate attack to grow the chain
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Consensus mRNA start codon...
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AUG (rarely GUG)
"AUG inAUGurates protein synthesis" |
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mRNA stop codons...
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UGA, UAA, UAG
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Gene site responsible for RNA polymerase binding...
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Promoter region
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Function of eukaryotic RNA polymerase I...
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synthesis of rRNA
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Function of eukaryotic RNA polymerase II...
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synthesis of mRNA
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Function of eukaryotic RNA polymerase III...
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synthesis of tRNA
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Capping occurs on which end of the pre-mRNA?
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5' addition of 7-methylguanosine
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Polyadenylation of pre-mRNA occurs on which end?
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3' addition of poly-A sequence
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Antibodies to spliceosomal snRNPs occur in what disease?
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SLE
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Amino acid is covalently bound to which end of the tRNA?
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3'
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MOA of tetracyclines...
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30S binding, preventing binding of aminoacyl-tRNA
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MOA of aminoglycosides...
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30S binding inhibits formation of the initiation complex
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MOA of chloramphenicol...
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Inhibits 50S peptidyltransferase
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MOA of Macrolides...
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Binds 50S and prevents translocation
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MOA of clindamycin...
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blocks peptide bond formation
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MOA of chloramphenicol...
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blocks peptide bond formation
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What cell phase transition do p53 and Rb normally inhibit?
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G1-S
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Defect in I cell disease...
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Lysosomal storage disorder; failure of Golgi apparatus to add mannose-6-phosphate to lysosomal proteins
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Pt presents with coarse facial features, clouded corneas, restricted joint movements and high plasma levels of lysosomap enzymes...
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I cell disease
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Pt presents with recurrent pyogenic infections, partial albinism and peripheral neuropathy...
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Chediak-Higashi syndrome; defect in microtubule polymerization leading to decreased fusion of phagosomes and lysosomes
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Findings in Kartagener's Syndrome...
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Immotile cilia results in male and female infertility, bronchiectasis, recurrent sinusitis; associated with situs invertus
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Type I collagen is found primarily in...
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Bone; also in skin, tendons, fascia, cornea, late wound repair
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Type II collagen is found primarily in...
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Cartilage; also in vitreous body and nucleus pulposus
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Type III collagen is found primarily in...
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Skin and blood vessels; also in uterus, fetal tissues and granulation tissue
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Type IV collage is found primarily in...
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Basement membrane
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Alport syndrome is a defect in...
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Type IV collagen
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Symptoms of Alport syndrome...
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progressive hereditary nephritis and deafness
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Vitamin C is required for what step of Collagen synthesis...
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hydroxylation of specific proline and lysine residues; deficit is scurvy
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Defect in osteogenesis imperfecta...
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Type I collagen defect
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Symptoms of osteogenesis imperfecta...
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multiple fractures (type I collagen is necessary for flexibility of bone), blue sclera, hearing loss (middle ear bone abnormality), dental imperfections (lack of dentin)
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Defect in Ehler's-Danlos syndrome...
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Type III collagen defect
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Symptoms of Ehler's Danlos syndrome...
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Hyperextensible skin, tendency to bleed, hypermobile joints; associated with joint dislocation, berry aneurysms, organ rupture
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Defect in Marfan's syndrome...
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defect in fibrillin - elastin
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Southern blotting tests for...
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DNA sample
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Northern blotting tests for...
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RNA sample
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Western blotting tests for...
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Protein
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Southwestern blotting tests for...
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DNA-binding proteins
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Pleiotrpy...
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One gene controls more than one effect
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Genetic imprinting...
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Phenotype depends on whether DNA defect is of maternal or paternal origin
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Locus heterogeneity...
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mutations at different loci produce that same phenotype
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Vitamin A deficiency results in...
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Night blindness, dry skin
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SE of vitamin A therapy...
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Teratogenic
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Vitamin A can be used to treat...
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Measels, AML subtype M3
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Vitamin B1 (thiamine) deficiency...
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Beriberi(Dry - polyneuritis, symmetrical muscle wasting; Wet - Dilated cardiomyopathy, edema); Wernicke-Korsakoff syndrome
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Triad of Wernicke-Korsakoff syndrome...
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Confusion, ophthalmoplegia, ataxia; caused by thiamine deficiency
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Vitamin B2 (riboflavin) deficiency...
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Cheilosis (inflammation of the lips, scaling and fissures at the corners of the mouth), Corneal vascularization
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Vitamin B3 (niacin) deficiency...
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Glossitis; severe deficiency - pellagra (classically diarrhea, dermititis, dementia)
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Causes of pellagra...
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Severe deficiency of Niacin (vitamin B3) - caused by Hartnup disease (decreased tryptophan absorption - required for synthesis), Malignant carcinod syndrome (increased tryptophan metabolism) or INH therapy (decreased vitamin B6)
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Vitamin B5 (pantothenate) deficiency...
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Dermatitis, enteritis, alopecia, adrenal insufficiency
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Vitamin B6 (pyridoxine) deficiency...
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Convulsions, hyperirritability, peripheral neuropathy, sideroblastic anemia (required in heme synthesis
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Vitamin B12 (cobalamin) deficiency...
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Macrocytic, megaloblastic anemia, hypersegmented PMNs, neurologic symptoms due to abnormal myelination
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Folic acid deficiency...
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Macrocytic megaloblastic anemia with NO neurologic symptoms (as opposed to Cobalamin)
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Vitamin E deficiency...
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Increased RBC fragility (hemolytic anemia), muscle weakness, posterior column and spinocerebellar tract demyelination
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Zinc deficiency...
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Delayed wound healing, hypogonadism, decreased adult hair, anosmia, distortion or loss of taste
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Limiting reagent in Ethanol metabolism...
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NAD+
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MOA of fomepizole...
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Inhibits ADH - antidote for methanol or ethylene glycol poisoning
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Mechanism of hypoglycemia in Ethanol consumption...
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EtOH increases NADH/NAD+ ratio in the liver, forcing formation of lactate and malate from pyruvate and oxaloacetate (respectively); this inhibits gluconeogenesis and stimulates fatty acid synthesis
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Fatty acid oxidation, acetyl-CoA production, TCA cycle and oxidative phosphorylation all take place in...
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Mitochondria
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Glycolysis, fatty acid synthesis, and HMP shunt all take place in...
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Cytosol
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Protein synthesis in eukaryotic cells mainly takes place in...
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Rough Endoplasmic Reticulum
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Steroid synthesis takes place in...
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Smooth Endoplasmic Reticulum
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Heme synthesis, Urea cycle and Gluconeogenesis all take place in...
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Both the mitochondria and the cytosol
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Odd-chain fatty acids and branched-chain amino acids enter the TCA cycle via which intermediate...
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Succinyl CoA (through propionyl-CoA and Methylmalonyl-CoA)
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NADPH is a product of what pathway? Used in what kinds of processes?
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HMP-shunt, used in anabolic reaction (steroid and fatty acid synthesis)
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Major location of Glucokinase...
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Liver and beta-cells of the pancreas; upregulated in response to insulin, and serves to help sequester excess glucose from the blood
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Defect in NADPH oxidase causes...
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Chronic granulomatous disease - defective respiratory burst
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Pts with chronic granulomatous disease are at increased risk of infections by...
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Catalase-positive species (S. aureus, Aspergillus, MTb, Listeria, Enterococci)
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Oxidizing agents that can cause hemolytic anemia in G6PD patients...
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Fava beans, sulfonamides, primaquine, anti-TB drugs
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Essential fructosuria is caused by...
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Defect in fructokinase
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Fructose intolerance is caused by...
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Defect in Aldolase B
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Symptoms of Fructose Intolerance...
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Hypoglycemia (depleted phosphate due to increase F-1-P), jaundice, cirrhosis, vomiting
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Symptoms of galactokinase deficiency...
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Infantile cataracts die to accumulation of galactitol in the lens
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Classic galactosemia defect...
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Absence of Galactose-1-P uridyltransferase
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Symptoms of classic galactosemia...
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Failure to thrive, jaundice, hepatosplenomegaly, infantile cataracts, MR
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Purely glucogenic amino acids...
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Methionine, valine, arginine, histidine
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Purely ketogenic amino acids...
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Leucine, lysine (used to treat Pyruvate Dehydrogenase deficiency)
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Glucogenic and ketogenic amino acids...
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Isoleucine, phenylalanine, threonine, tryptophan
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Defect in Phenylketonuria...
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Decreased Phenylalanine hydroxylase or decreased tetrahydrobiopterin cofactor
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Symptoms of PKU...
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MR, growth retardation, seizures, eczma, musty body odor; tyrosine becomes an essential amino acid
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Defect in Alkaptonuria...
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Deficiency of homogentisic acid
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Tyrosinase deficiency results in...
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Albinism, due to defective synthesis of melanin from tyrosine/DOPA
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Causes of homocystinuria...
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Cystathionine synthase deficiency, decreased affinity of cystathionine synthase for pyridoxal phosphate, homocysteine methyltransferase deficiency
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Treatment of cystathionine synthase deficiency...
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decrease Methionine, increase cystine, B12 and folate in diet
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Treatment of Homocystinuria due to decreased affinity of cystathionine synthase for pyridoxal phosphate...
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greatly increase vitamin B6 in diet
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Defect in Maple syrup urine disease...
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blocked dgradation of branched-chain amino acids (Isoleucine, leucine, valine)
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Function of ApoE...
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Mediates remnant uptake
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Fuction of ApoA-I...
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Activates LCAT
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Function of ApoC-II
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Lipoprotein Lipase Cofactor
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Function of ApoB-48...
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Mediates chylomicron secretion
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Function of ApoB-100...
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Binds LDL receptor
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Type I familial dyslipidemia (hyper-chylomicronemia) caused by...
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Lipoprotein lipase deficiency or defect in ApoC-II (LPL cofactor)
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Symptoms of hyper-chylomicronemia...
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Pancreatitis, hepatosplenomegaly, eruptive/pruritic xanthomas (no risk for increased atherosclerosis)
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Type IIa familial dyslipidemia (familial hyper-cholesterolemia) caused by...
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Absent or greatly reduced LDL receptors
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Symptoms of familial hyper-cholesterolemia...
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Accelerated atherosclerosis, tendon xanthomas, corneal arcus
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Type IV familial dyslipidemia (hyper-triglyceridema) caused by...
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Hepatic overproduction of VLDL
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Familial hyper-trglyceridemia causes...
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pancreatitis
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