Exam II Pt. 9

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Exam II Pt. 9
2013-10-13 13:54:05
Required Reading

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  1. a.       Proteoglycans
                                                                  i.      __ complex
                                                                ii.      consists of a core protein to which chains of __are covalently attached
    1.      each is composed of a repeating disaccharide: __, where A and B represent two different sugars
    2.      __are higly acidic due to the presence of both __ and __ groups attached to the sugar rings
    • protein-polysaccharide
    • glycosaminoglycans 
    • A-B-A-B-A-
    • GAGs 
    • sulfate and carboxyl
  2.                                                               i.      proteoglycans of the ECM may be assembled into gigantic complexes by __ of their __ to a molecule of __, a nonsulfated GAG
                                                                ii.      Because of the negative charges borne on the __, __bind huge numbers of __, which in turn bind large numbers of water molecules
    • linkage
    • core proteins
    • hyaluronic acid
    • sulfated GAGs

    • proteoglycans 
    • cations
  3. 1.      as a result, proteoglycans form a __ that __ and __

    a.       this property complements that of the adhacent collagen molecules, which __ and __
    porous, hydrated gel

    fills the EC space and resists crushing forces

    resist pulling forces and provide a scaffold for the proteoglycans
  4.                                                               i.      Together, __ and __ give __and other EC matrices strength and resistance to deformation
                                                                ii.      the EC matrix of bone is also composed of __ and __, but it becomes hardened by impregnation with __
    1.      both __ and __ are taken widely as health supplements with the aim of improving the condition of skin and joints
    • collagen and proteoglycans
    • cartilage 
    • collagen and proteoglycans
    • calcium phosphate salts
    • sulfated and nonsulfated GAGs
  5. a.       Fibronectin
                                                                  i.      __= a structure made up of a network of interacting components
                                                                ii.      consists of a linear array of distinct “__” that gives each polypeptide a __construction
                                                              iii.      each is constructed from a sequence of approx __
    1.      __ found as part of many other proteins
    • matrix
    • building blocks
    • modular 
    • 30 independently folding Fn modules
    • Fn-type modules
  6.                                                               i.      presence of shared segments among diverse proteins suggests __
                                                                ii.      in __, the 30 or so structural modules combine to form __
    • evolution
    • fibronectin
    • five or six larger functional domains
  7.                                                               i.      each of the two polypeptide chains that make up a firbonectin molecule contains:
    • 1.      binding sites for numerous components of the ECM which facilitate interactions that link these diverse molecules into a stable, interconnected network
    • 2.      binding sites for receptors on the cell surface, which hold the ECM in a stable attachment ot the cell
  8. a.       binding activities of fibronectin molecules are enhanced by __ that pull on these fibrous proteins and unfold its component molecules, which __ the __
    • mechanical forces
    • exposes the binding sites
  9.                                                               i.      importance evident during __, which Is characterized by waves of cell __during which different cells follow different routes from one part of the embryo to another
    1.      migrating cells are guided by proteins
    a.       ex: neural cell migration
    • embryonic development
    • migration
  10. a.       Laminin
                                                                  i.      family of __ that consist of __ linked by __ and organized into a molecule resembling a cross with three short aarms and one long arm
                                                                ii.      at least __identified
                                                              iii.      __ influence cell’s potential for migration, growth, and differentiation
    • extracellular glycoproteins
    • three different polypeptide chains
    • disulfide bonds
    • 15 
    • extracellular laminins
  11.                                                               i.      in addition to binding tightly to cell-surface receptors, they bind to other __, to __, and to other components of __
                                                                ii.      __ and __ molecules of absement membranes form separate, but interconnected, networks
    1.      these interwoven networks give basement membranes both __ and __
    • laminin moeclues
    • proteoglycans
    • basement membranes
    • laminin
    • type IV collagen

    strength and flexibility
  12. a.       Dynamic properties of the ECM
                                                                  i.      can do what as they are pulled on by cells and contract when tension is relieved
                                                                ii.      components are subject to continual __ and __, which renew the matrix and allow remodeling
    • stretch several times their normal length
    • degradation and reconstruction
  13.                                                               i.      __carried out __ that are either secreted into the EC space or anchored to the plasma membrane
    1.      as a group, these can do what although as  individual family members cannot
    2.      thought to be involved in tissue remodeling, etc.
    3.      excessive activity- disease like arthritis, tooth and gum disease, etc. 
    • degradation 
    • matrix metalloproteinases 
    • digest nearly all of the ECM components