Lecture 3

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Question 1 of 33

What are the different types of load? (6) = Compression , torsion , bending , sheer , tension , combined

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Question 2 of 33

"What is the most abundant collagen fibre? = Type I (90%)"

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Question 3 of 33

Where is type I collagen found (3) = Tendons, ligaments, bone

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Question 4 of 33

Where is type II collagen found? (3) = Cartilage eye (vitrous humour), intravertebral discs

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Question 5 of 33

Where is type III collagen found? (2) = Reticular fibres, skin

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Question 6 of 33

What do type IV collagen fibres form? = Basal lamina of epithelial tissue

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Question 7 of 33

What are the major steps of collagen fibre formation? (4) = Synthesis of pro-alpha protein chain, assembly of three pro-alpha chains into procollagen triple helix, assembly into fibril, aggregation of fibrils into fibre

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Question 8 of 33

What does the pro-alpha chain contain? (3) = Glysine, proline, lysine

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Question 9 of 33

What happens to pro collagen to allow it to form triple helices? = Hydroxylation (formation of H bonds)

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Question 10 of 33

What prevents pro-collagen triple helices from bind with other pro-collagen triple helices?  = Propeptides bind to the ends of the helices

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Question 11 of 33

What happens to the pro-collagen after it leaves the cell? = Propeptides cleaved

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Question 12 of 33

Which amino acid is most important in collagen? = Glysine

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Question 13 of 33

Where does the strength of collagen come from? (3) = Glysine enables light coiling, hydroxylation forms helices, covalent bonds

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Question 14 of 33

What causes scurvey? = Vitamin C deficiency

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Question 15 of 33

What does a vitamin C deficiency result in? = Downregulated production of lysyl hydroxylase (for hydroxylation of proline and lysine)

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Question 16 of 33

What is the result of downregulation of production of lysyl hydroxylase? = Collagen does not form it’s essential coiled structure and loses its strength

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Question 17 of 33

What are the symptoms of weakened collagen fibres caused by vit C deficiency? (3) = Rotting teeth, bleeding from mucous membranes, bowed legs

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Question 18 of 33

What is osteogenesis imperfecta? = Mutation of genes that encode collagen type I fibres

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Question 19 of 33

What are the symptoms of osteogenesis imperfecta? ((2) = Brittle bones, Weak tendons

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Question 20 of 33

What is stickler syndrome? = An autosomal dominant inherited mutation of genes that encode collagen type II fibres

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Question 21 of 33

What are the symptoms of stickler syndrome? (4) = Flat face, vision impairment, hearing loss, osteoarthritis 

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Question 22 of 33

What is a proteoglycan? (2) = Core protein, Covalently attached glysosaminoglyan chain (GAG)

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Question 23 of 33

What determines the properties of proteoglycans? (2) = Number of GAGs, type of GAGs

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Question 24 of 33

What are the types of proteoglycans? (4) = Aggrecan, Biglycan, Perlecan, Versican

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Question 25 of 33

What GAG is not sulphated? = Hyaluronan

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Question 26 of 33

What are the properties of GAGs? (2) = Negatively charged, hydrophilic

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Question 27 of 33

What binds proteoglycans to hyaluron molecules? = Link proteins

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Question 28 of 33

What is GAG is aggrecan rich in? = chondroitin sulfate 

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Question 29 of 33

Where is aggrecan commonly found? (2) = Cartilage, invertebral discs

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Question 30 of 33

What enzymes are active in collagen degradation? (2) = Metalloproteases (MMPs), Collagenases

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Question 31 of 33

Which enzyme breaks down proteoglycans? = ADAMTS

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Question 32 of 33

What are examples of collagenases? (2) = MMP1, MMP13

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Question 33 of 33

What are examples of aggrecanases? (2) = ADAMTS-4, AMDAMTS-5

Question 33 of 33