Biochem Part I Flashcards
Which aa are necessary to make purines
GAG - glycine, apartarte, glutamine
Thymine has a what?
methyl group
Difference between cytosine and uracil?
Deamination of cytosine => uracil
Lesch Nyan syndrome?
Defective purine salvage due to absence HGPRT. Inability to convert hypoxanthine to IMP and guanine to GMP. Excess Uric acid => gout. HGPRT - hyperuricemia, Gourt, Pissed off (self mutilation), R - Retardation, T - dysTonia
Which aminoa acids are coded by only 1 codon
Methionine (AUG), tryptophan (UGG)
DNA Pol III and DNA Pol I functions? Which one has 3-5’ proof reading capabiltiies?
DNA Pol III: Elongates by adding deoxynucleotides to the 3’ end. Elongates lagging strand until it reaches primer of preceding fragment. Also has 3’-5’ proof eading capabilities. DNA pol 1 removes RNA primer and adds DNA.
Mismatch repair is defective in?
HNPCC. Mismatch repair is normally => newly synthesized strand is recognized, mismatched nucleotides are removed and the gap is filled and resealed
What is I-cell disease?
Inherited lysosomal storage disorder. Defect in phosphotransferase and unable to phosphorylate mannose. Mannose 6 phosphate necessary to traffic to lysosomes. Proteins are delivered extracellulary instead of lysosomes. PPT: Coarse facial features, clouded corneas, restricted joint movement, high plasma levels of lysosomes enzymes
SRP direct proteins from where to where?
ribosomes to RER
What drugs act on microbutubles
Microtubules Get Constructed Very Poory: Mebendazole Griseofulvin Colchicine (anti-gout) Vincristine/Vinblastine Paclitaxlel
These stain for what? Desmin, Vimentin, GFAP, cytokeratin, neurofilaments
Muscle, connective tissue, glial cells, eptihelial cells, neurons
Mnenomic for rememembering Collage locations
Be cool, read books - Bone (Skin, tendon), Cartilage, Reticulin, Basement membrane
Type 1 collagen found in?
Bone, skin, tendon, ligaments, dentin, cornea, blood vesslels, SCAR TISSUE
TYPE 2 collagen found in?
Cartilage, vitreous humor, nucleos pulposus
Type 3 collagen found in? Type 4?
Reticulin - BLOOD VESSELS, Skin, lungs, intestine, bone marrow, lymphatics, and granulation tissue. Type 4 = basement membrane
What gives elastin its elastic properties
Some lysine residues form covalent crosslinkes - 4 different lysines on 4 diferent elastin chains accomplished by extracellular lysyl hydroxylase
Direct vs Indirect ELISA
Direct Elisa: use a test ANTIBODY to see if the antigen is present. Second antibody linked to a color generating enzyme is added to detect the antigen. Indirect Elisa: use a test antigen to see if the antibody is present. Second antibody coupled to color generating enzyme is added to detect the first antibody
What is cre-lox system?
Inducibly manipulate genes at specific development points
What is RNA interference?
dsRNA is synthesized complementary to mRNA of interest. dsRNA infected into human cells, separates and degrades target mRNA
Isodisomy and Heterodisomy are from what kinds of error?
Isodisomy = meisos II, heterodisomy = meiosis I
In Hardy Weinberg, the frequency of X linked recessive diseae in Males and females is what?
q= males, q^2 females
What is Osler Weber Rendu Syndrome
Hereditary hemorrhagic telangiectasia - A/D. inherited disorder of blood vessels. Telangiectasia, recurrent epistaxis, skin discolorations, AVMs, BI bleeding, hematuria
Mnemonic to remember X linked recessive
Be Wise Foods GOLD heeds silly hope. Bruton’s x ilnked agammaglobulinemia, wiskott-aldrich, Fabry disease, G6PD deficiency, Ocular albinism, Lesch-Nyan, Duscene and Becker muscular dystrophy, Hunter Syndrome, Hemophilia A and B, Ornithine transcarbamylase deficiency
What is Fragile X syndrome? Defect? PPt?
Trinucleotide disorder = CGGn. X-linked defect affecting methylation and expression of FMR1 gene. 2nd most common cause of intellectual disability after Down syndrome. Findings: large testes, long face with long jaw, large everted ears, autism, mitral valve prolapse, short height, joint laxity, scoliosis
