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41 Cards in this Set
- Front
- Back
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extracellular matrix |
an organized meshwork of macromolecules surrounding and underlying cells; consists of ground substance and fibres |
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ground substance |
component of ECM that contains glycosaminoglycans, proteoglycans, and glycoproteins |
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glycosaminoglycans |
long, unbranched polysaccharids composed of repeating disaccharide units; always includes an amino sugar; strong negative charge; resist compression |
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urionic acid sugar |
sugar which has a carboxyl group and is often present in glycosaminoglycans |
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hyaluronic acid |
a large, nonsulfated glycoaminoglycan; it is not attached to a core protein |
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chondroitin sulfate |
a glycosaminoglycan present in cornea, cartilage, bone, adventitia of arteries; sulfated and linked to a core protein |
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dermatan sulfate |
a glycosaminoglycan present in the skin, blood vessels, and heart valves; sulfated and linked to a core protein |
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heparin |
a glycosaminoglycan present in lung, skin, liver, and mast cells; sulfated and linked to a core protein |
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heparan sulfate |
a glycosaminoglycan present in the basal laminae, lungs, arteries, and cell surfaces; sulfated and linked to a core protein |
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keratan sulfate |
a glycosaminoglycan present in the cornea, cartilage, and nucleus pulposus of intervertebral discs; sulfated and linked to a core protein |
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proteoglycan |
a core protein from which many glycosaminoglycans extend; shaped like a bottle brush; act as binding sites for signalling molecules, and confer selective permeability to ECM |
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matrix fibronectin |
an adhesive glycoprotein that forms fibrils in the extracellular matrix; has binding sites for collagen, heparin, and cell surface receptors |
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cell-surface fibronectin |
a glycoprotein that transiently attaches to the surface of cells; mediates cell adhesion |
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plasma fibronectin |
a circulating plasma glycoprotein which functions in blood clotting, wound healing, and phagocytosis |
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laminin |
a cross-shaped glycoprotein located in the basal (external) lamina that is synthesized by epithelial cells; has binding sites for integrins, heparan sulfate, collagen IV, and entactin; anchors epithelial cell to basal lamina |
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entactin |
a glycoprotein component of all basal (external) laminae; binds laminin; links laminin with collagen IV in the lamina densa |
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tenascin |
an adhesive glycoprotein; most abundant in embryonic tissue; secreted by glial cells in developing nervous system; promotes cell-matrix adhesion, cell migration |
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chondronectin |
a glycoprotein in cartilage; attaches chondrocytes to collagen II; binds collagen, proteoglycans, integrins |
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osteonectin |
a glycoprotein found in bone; links minerals to collagen I and influences calcification |
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fibronectin receptors |
cell receptors that belong to the integrin family of receptors; bind fibronectin extracellularly and actin intracellularly |
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collagen |
the most abundant structural protein of the ECM |
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preprocollagen synthesis |
stage of collagen synthesis that occurs in the RER from mRNA |
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hydroxylation |
step of collagen synthesis which occurs in the RER and involves action on prolines and lysines to form polypeptide chains; requires vitamin C as a cofactor |
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glycosylation |
step of collagen synthesis involving attaching sugars to hydroxylysine in the RER |
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procollagen formation |
step of collagen synthesis involving triple-helix formation in the RER; regulated by propeptides of alpha chains |
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addition of carbohydrates |
step of collagen synthesis which occurs in the Golgi apparatus |
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cleavage of procollagen |
step of collagen synthesis occurring in ECM; catalyzed by procollagen peptidase; propeptide sequence is removed; yields tropocollagen |
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self assembly of tropocollagen |
step of collagen synthesis involving aggregation of tropocollagen near cell surface to form fibrils |
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cross-linking |
step of collagen synthesis which occurs between adjacent tropocollagen molecules and invovles formation of lysine and hydroxylysine-derived aldehydes |
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collagen I |
collagen present in dermis, bone, tendons, ligaments, and fibrocartilage; synthesized by fibroblasts; resists tension |
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collagen II |
collagen present in hyaline cartilage; synthesized by chondroblasts; resists intermittent pressure |
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collagen III |
collagen present in lymphatic system, cardiovascular system, liver, lung, spleen, intestine, uterus, and endoneurium; synthesized by fibroblasts; forms structural framework in expandable organs |
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collagen IV |
collagen present in the basal lamina; synthesized by endothelial cells and epithelial cells; provides support and filtration |
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collagen V |
collagen present in placenta; synthesized by mesenchymal cells; unknown function |
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collagen VII |
collagen present in dermal-epidermal junctions; synthesized by keratinocytes; forms anchoring fibrils that secure the lamina densa to underlying connective tissue |
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elastin |
an amorphous structural elastic protein which imparts elasticity to the ECM; composed mostly of desmosine and isodesmosine; cross-linked via lysine residues |
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fibrillin |
a glycoprotein which organizes elastin into fibers and is the main component of peripheral microfibrils |
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fibroblasts, smooth muscle cells, chondrocytes, chondroblasts |
cells that secrete elastic fibres |
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scurvy |
vitamin C deficiency; involves synthesis of poorly hydroxylated tropocollagen; symptoms include bleeding gums and eventual tooth loss |
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fibronectin "tracks" |
structures formed by fibronectin along which cells migrate; involved in wound healing in connective tissue and epithelia |
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Ehlers-Danlos type IV syndrome |
a syndrome resulting from a genetic defect of transcription or translation of collagen III; causes ruptured bowel and/or large arteries, where collagen III surrounds smooth muscle cells |
