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Glycocalyx ..
- 1. provide mechanical support
- 2. barriers to particles
- 3. binding site for regulatory factors
- 4. mediate cell interactions
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epithelial cells
cell lining spaces in the body
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connective tissues
composed to nonliving extracellular materials
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proteins in the plasma membrane have...?
sugars attach to it
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extracelluar matrix...
organized network of materials located beyond the plasma membrane
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basement membrane...
- thick region around the ECM
- -surrounds muscle/fat
- -underlies the basal surface of epithelial tissues
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basement membranes...
- 1. separate different tissues
- 2. provide mechanical support
- 3. barrier to macromolecule and cellular movement
- 4. substrate for cell migration
- 5. generate signals that maintain cell survival
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collagens..
have 27 different types
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collagens provides...
- -high tensile strength (resistant to pulling forces)
- -alpha helical trimers bundle together into fibrils
- -type I, II, III, (fibrillar) form rigid cables
- -type IV (nonfibrillar) can form an interconnected lattice
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Type I, II, III of collages are..
- adjacent collagens are strengthened by covalent cross-links
- ----hydroxylysine - lysine
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collagens binds...
fibronectins and integrins (cell surface)
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collagens with type IV have..
- composed of helical and non-helical segments (felxibility)
- and globular domains at each end (lattice contact points)
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diseases that are caused by defects in the collagen genes
- 1. Osteogenesis imperfecta: fragile bones
- 2. Ehlers-Danlos syndrome: hyperflexible joints, highly extensible skin
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proteoglycans.
- = protein core + glycosaminoglycan (GAG) plysaccharide complex
- -hyaluronic acids links many proteoglycans to form extremely large molecules
- -fill the scaffold created by collagens
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proteoglycans
- -chondroitin sulfate & karetin sulfate
- -high amt of negative charge binds cations and H2O
- -hydrated gel resists compressive forces
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fibronectins
- -modular domains for interactions
- - bind collagens, proteoglycans, integrins at cell surface
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importance of fibronectins
- -linking ECM components together
- -cell attachment to matrix
- -cell migration
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laminins are..
-3 polypeptides linked by disulfide bonds
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