BIOL 200 Lecture Notes - Lecture 14: Turgor Pressure, Cell Membrane, Pectin
31 Mar 2018
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Document Summary
Tissues and extracellular matrix: multicellular organisms, have many cells bound together, often have specialized groups of cells, tissues, organs, cell-to-cell adhesion, cell-to-extracellular matrix adhesion, depend on cytoskeleton and related structures for strength, stability, and organization. Cytoskeleton and ecm are connected: transmembrane proteins link ecm to cytoskeleton. Integrins: tm proteins that bind extracellular fibronectin and intracellular adaptor proteins: fibronectin has collagen binding sites (ecm, adaptor proteins bind actin microfilaments (cortex, extracellular binding of integrins is activated by intracellular binding of cytoskeleton. Ecm also contains carbohydrates: gels of polysaccharides fill ecm, gel-like matrix resists compression and holds water (cid:894)think (cid:862)sho(cid:272)k a(cid:271)sor(cid:271)er(cid:895, long-chain polysaccharides linked with proteins form huge molecular aggregates. Include proteoglycans (protein plus carbohydrate chains called glycosaminoglycans: largest aggregates are aggrecans, proteoglycans attached to large carbohydrate hyaluronan molecules, aggrecans are made of hyaluronan and proteoglycan. Separate different ends of cells: apical and basal surfaces. Membranes of adjoining cells tightly (cid:862)stit(cid:272)hed(cid:863) together (cid:271)y tra(cid:374)s(cid:373)e(cid:373)(cid:271)ra(cid:374)e proteins.
