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13 Cards in this Set
- Front
- Back
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what are the main roles of collagen and elastin? are they globular or fibrous?
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structural proteins, both are fibrous
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What is the most abundant protein in our body? What structure does it have?
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collagen, it is a quaternary protein that is made up of 3 alpha chains
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what are the groups of collagen? which is most abundant?
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fibril forming collagens I II III
network forming collagen IV V (mesh arranged) fibril supporting collagen IX XII *type I is most abundant |
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what is the basic structural unit of type I? what two amino acids is it made of? what percentages?
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tropocollagen which is made up of 3 intertwined polypeptide chains. it is 33% glycine and 10% proline. each chain is in a left-handed helix and are wounded into one another into one super right handed helix
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what are hydroxyproline and hydrolysine important for?
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these molecules occur after translation of the protein. they are important for strength and tensility of collagen
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hydroxyproline
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there are hydrogen bonds between strands, and the enzyme requires VIT C...for strengthening of collagen bonds. this molecule stabilizes the triple helix
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hydroxylysine
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involves carbohydrate addition, and forms covalent links between triple strands
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how does cross-linking of collagen work?
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the collagen forms fibrils which create a striated pattern. the white areas have little to no overlap, and the dark bands create significant overlap. strength occurs as a result of cross linking.
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what are the steps of collagen processing?
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1. removal of signal sequence
2. disulfide bond formation 3. 4. hydroxylation of proline/lysine AND CHO addition 5. triple helix formation 6. secretion 7. removal of propeptides (tropocollagens) 8. spontaneous fibril formation and cross-linking |
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which enzyme is required for extracellular cross-linking of collagen fibrils?
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lysyl oxidase
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What is scurvy? what does type VI disease have a deficiency in?
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a collagen disorder in which no hydroxyproline is formed because there is a Vitamin C deficiency,
deficiency in lysyl hydroxylase which causes problems in joint issues |
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What is Elastin made up of? What are the other characteristics?
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700 residues, it is rich in proline and lysine, there is little hydroxyproline, and no hydroxylysine
desmosine-type crosslinks it has a coiled, relaxed form, and a long/stretched active form |
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how does emphysema occur?
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lack of inhibition of elastase?
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