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37 Cards in this Set
- Front
- Back
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How many protein chains can form collagen fibrils?
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1,2 or 3
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What is the arrangement of collagen proteins in tendons?
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Parallel bundles
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What is the arrangement of collagen proteins in skin?
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Sheets at various angles
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What is the importance of the arrangement of collagen fibrils in the cornea?
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Planar sheets at varying angles to minimize light scattering
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Where is type I collagen found?
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Skin, bone, tendon, blood vessels cornea
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Where is type II collagen found?
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Cartilage, intervertebral disc, vitreous body
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Where is type III collagen found?
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blood vessels, fetal skin
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Where is type IV collagen found?
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Basement membrane
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Where is type VII collagen found?
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Beneath stratified squamous epithelia
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Where is type IX cartilage found?
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Cartilage
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Where is type XII collagen found?
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Tendon, ligaments
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What amino acid sequence is found in collagen alpha chains?
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Gly-X-Y
*X = typically proline Y= hydroxyproline |
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What is the importance of glycine in collagen function?
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Mutation of glycine causes human collagen diseases
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What stabilizes the triple helix?
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Hydrogen bonds
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When do collagen diseases result?
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-When exons are skipped/deleted
-introns are not removed |
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What mutation causes osteogenesis imperfecta?
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Mutation in one of the two alpha chains of collagen type I
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What causes scurvy?
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Ascorbate deficiency (vitamin C)
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What enzymes require ascorbate? (Vit. C)
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Prolyl hydroxylase and lysyl hydroxylase
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What is osteolathyrism?
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A condition that results from failure to cross-link b/e collagen fibrils
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what is beta-aminopropionitrile?
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Found in sweet peas, inactivates lysyl oxidase by forming a covalent bond w/ the active site
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What enzyme requires copper to function?
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Lysyl oxidase
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What is elastin?
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A fibrous protein that is insoluble in water that is rich in proine and lysine
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What does elastin assemble on?
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A scaffold composed of fibrillin (a glycoprotein)
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What is elastomeric?
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Can stretch in any direction and return to its original shape.
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What amino acid is located every 3rd amino acid in collagen?
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Glycine
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What amino acid in collagen causes the left-handed helix?
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Proline/hydroxyproline
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What amino acid gives collagen flexibility?
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Glycine
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Mutation of what collagen amino acid is most likely to result in a genetic disease?
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Glycine
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In which direction does collagen synthesis go? why is this important?
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C terminus to N terminus; this is important b/c it means you have to synthesis the entire molecule before assembling the collagen.
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What inhibits the peptidyl-prolysl cis-trans-isomerase?
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Cyclosporin A
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How does nucleation, propagation of collagen begin?
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By association of C-terminal globular domain.
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What reactions are important for formation of the collagen triple helix?
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post-translational modification reactions
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What is the importance of oxidizing lysine residues?
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It allows cross-linking interactions b/e collagen fibers
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What cross-links does elastin have?
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Many desmosine cross-links
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What regions give elastin its stretchiness?
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The hydrophobic domains in elastin
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What inhibits neutrophil elastase?
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Alpha-1-antitrypsin
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How does smoking affect neutrophil elastase?
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Oxidizes methionine residue. The oxidized alpha-1-antitrypsin does not inhibit neutrophil elastase
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