Exam II Pt. 7

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Exam II Pt. 7
2013-10-13 13:21:08
Required Reading

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  1. a.      __: when lymphocytes removed from body and injected back would return ot sites where they originally were

    lymphocyte homing
  2. b.      __comprise a family of integral membrane glycoproteins that recognize and bind to a particular arrangement of __that project from the surfaces of other cells                                                              i.      the name of this class of __ is derived from “__,” a general term for a compound that binds ot specific __groups
    • Selectins 
    • sugars in the oligosaccharides 
    • cell-surface receptors
    • lectin
    • carbohydrate
  3. a.      __ possess a small __, a __, and a large __ segment that consists of a number of separate modules, including an outermost domain that acts as the __
                                                                  i.      three known selectins: __
    • Selectins
    • cytoplasmic domain
    • single membrane-spanning domain
    • extracellular
    • lectin
    • E-selectin (endothelial cells); P-selectin (platelets and endothelial cells);  L-selectin (leukocytes)
  4. 1.      all three selectins recognize a particular grouping of __at the ends of the __ of certain complex __
    a.      binding of selectins to their carbohydrate ligands requires __
    • sugars 
    • carbohydrate cahains
    • glycoproteins
    • calcium
  5. a.      as a group, selectins mediate __between circulating leukocytes and vessel walls at sites of __
    b.      selectins are well-suited for __ because the bond that they form with their __ become stronger when the __
    • transient interactions 
    • inflammation and clotting
    • capturing fast moving particles
    • ligands
    • interaction is under mechanical stress
  6. a.      antibodies, a type of protein called __, were found to consist of polypeptide chains composed of a number of similar domains
                                                                  i.      each of these __ is composed of __ organized into a tightly folded structure
    • Ig
    • Ig domains
    • 70-110 amino acids
  7. a.      as a group, these proteins are members of the __
                                                                  i.      most members are involved in different __functions, but some of these proteins mediate __
    1.      originally evolved as __ and only secondarily took on their functions as __ of the vertebrate immune system
    immunoglobulin superfamily, or IgSF


    calcium-independent cell-cell adhesion

    cell-adhesion mediators

  8. a.      most IgSF cell-adhesion molecules mediate the specific interactions of __
                                                                  i.      still, some IgSF members, like __, mediate __between __ cells. 
    • lymphocytes with cells required for immune response
    • VCAM, NCAM, and L1,
    • adhesion 
    • nonimmune
  9. 1.      NCAM and LI play important roles in __, __, and other events during the development of the NS
    a.      like __and other proteins in cell adhesion, the IgSF cell-adhesion molecules have a __ and are composed of individual domains of similar structure to domains in other proteins 
    • nerve outgrowth, synapse formation
    • fibronectin 
    • modular constructuion
  10. a.      importance of L1 in neural development revealed in several ways
                                                                  i.      mutations—> __ (water in the brain), mental retardation, etc.
                                                                ii.      __: missing two large nerve tracts
    b.      various types of proteins serve as __for IgSF cell-surface molecules
                                                                  i.      most integrins facilitate __of cells to their __, but a few integrins mediate __ by binding to proteins on other cells 
    • hydrocephalus
    • L1-deficiency disease
    • ligands 
    • adhesion 
    • substratum
    • cell-cell adhesion
  11. What are cadherins?
    a.      large family of glycoproteins that mediate Ca2+- dependent cell-cell adhesion nd transmit signals from the ECM to the cytoplasm
  12. __ typically join cells of similar type to one another and do so by binding to the same __ present on the surface of the neigbhboring cell
    cadherins x2
  13. 1.      this property was first demonstrated by genetically engineering cells that were normally nonadhesive to express one of a variety of different cadherins
    a.      cells then mixed in various combos and their interactions monitored
                                                                                                                                          i.      cells expressing one species of __ adhered to other cells expressing the same __
    • cadherin
    • cadherin
  14. a.      __ construction
    b.      types?
                                                                  i.      “__”; contain a relatively large extracellular segment consisting of __domains of similar size and structure, a signgle transmembrane segment,a dn a small __

    • modular
    •  E-cadherin, N-cadherin (neural), and P-cadherin (placental)

    • classical
    • five tandem 
    • cytoplasmic domain
  15. 1.      the __ is often associated with members of the __family of cytosolic proteins, which have a dual role: __
    • cytoplasmic domain
    • catenin 
    • tether cadherins to the cytoskeleton and transmit signals to the cytoplasm and nucleus
  16. a.      __from the same cell-surface associate laterally to form __
    b.      __ form bridges between successive domains of a given molecule, maintaining the extracellular portion of each __in a rigid conformation required for cell adhesion
                                                                  i.      adhesion between cells results from the interaction between the extracellular domains of cadherins from opposing cells to form a “cell-adhesion zipper”
    • cadherins 
    • parallel dimers
    • calcium ionscadherin
  17. a.      different types of cells bearing different __likely engage in different types of __
    the greater the number of interacting __ in a cluster, the greater the __ between apposing cells     
    • cadherins 
    • interactiosn
    • cadherins
    • strength of adhesion
  18. a.      cadherin-mediated adhesion is responsible for the ability of __
    b.      they may be the single most important factor in moldng cells into __ in the embryo and holding them together in the adult
                                                                  i.      the loss of cadherin function à __
    • like cells to “sort out” of mixed aggregates
    • cohesive tissues
    • malignant tumors
  19. a.      __ is characterized by change, in gene expression, cell shape, motility, etc.
                                                                  i.      __mediate many changes in __that are required to construct the tissues and organs of an embryo, called __
    1.      ex: epithelial-mesenchymal transition: epithelial cells form into mesenchyme or vice versa, which will eventually give rise to mesodermal tissues like blood, muscle, and bone
    • embryonic development
    • cadherins 
    • adhesive contacts 
    • morphogenesis
  20. a.      cells of the __(the cohesive epithelial layer) at the dorsal surface of the early embryo display __ on their surface, which promote close association with one another
    • epiblast 
    • E-cadherins
  21. a.      formation of NS is characterized by changes in __ where, following __, the dorsal surface is covered with a single-celled epithelial layerà __ tissues
                                                                                                                                          i.      at this point, they stop expressing__ and begin expressing __
    • cadherin expression,
    • gastrulation
    • ectodermal
    •  E-Cadherin
    • N-cadherin
  22. a.      whereas __are typically distributed diffusely all along the surfaces of two adherent cells, they also participate in the formation of specialized __
    • cadherins 
    • intercellular junctions