RR Final 5 Microtubules 4

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RR Final 5 Microtubules 4
2013-11-23 01:12:56
Cell Bio

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  1. Cilia and flagella structure
    •                                                               i.      hairlike, motile organelles that project from the surface of a variety of eukaryotic cells 
    • 1.       prokaryotici flagella are simple filaments that bear no evolutionary relationship to their eukaryotic counterparts

    They are both the same structure
  2. 1.       cilia can be likened to an __with direction __to cilium itself
    a.       in its __, the cilium is maintained in a __ as it pushes against the surrounding medium
    b.      in its __, it becomes __, offering little resistance to the medium
    • oar 
    • perpendicular 
    • power stroke
    • rigid state
    • recovery stroke
    • flexible
  3. Cilia continued:

    a.       occur in large numbers and their beating activity is __
    b.      cilia do what?
    c.       not all cilia are __: many cells of the body contain a __ that is thought to have a sensory function, __
    • coordinated
    • move fluid and particulate material through various tracts
    • motile
    • single nonmotile cilium (primary cilium)
    • monitoring the mechanical and chemical properties of extracellular fluids
  4. Flagella are in __ or __ and have __.

                                                                  i.      the entire __ or __ is covered by a membrane that is __l
    1.       the core of the cilium, called the __, contains an array of microtubules that runs __through the entire organelle
    a.       with rare exceptions, the __ consists of __ surrounding a __ of single microtubules
    • singles
    • pairs
    • different beating patterns
    • ciliary or flagellar projection
    • continuous with the plasma membrane of the cell
    • axoneme
    • longitudinally 
    • axoneme of a motile cilium or flagellum
    • nine peripheral doublet microtubules
    • central pair
  5.                                                                                                                                       i.      this same microtubular structure, called the __, is seen in __from protists and mammals and supports the common ancestor
    1.       all microtubules of the __have the same __: their plus ends are at the __ and their minus ends at the __
                                                                                                                                        ii.      each peripheral doublet consists of __, and one __, the latter containing 10 or 11 and not the usual 13
    • 9+2 array
    • axonemes 
    • axoneme 
    • polarity
    • tip of the proection
    • base
    • one complete microtubule, the A tubule
    • inclomplete, the B tubule,
  6.                                                               i.      the basic structure of the __was described by Irene Manto (plants) and Don Fawcett and Keith Porter (animals)
    1.       the __ were seen to be enclosed by the __, which is connected to the__ of the __ by a set of __, which are connected to one another by an __ composed of an elastic protein, __
    a.       arms (outer and inner) project from the __
    • axoneme 
    • central tubules
    •  A tubules
    • peripheral doublets
    • radial spokes
    • interdoublet bridge
    • nexin
    • A tubule
  7.                                                               i.      cilia and flagella extend from __
    1.      __ of the __ elongate to form the __of the cilium or flagellum
    a.       if the cilium or flagellum is sheared from the surface of a living cell, what happens?
    2.       as with other microtubular structures, the growth of an __occurs at the __(outer) ends of its microtubules
    • basal body
    •  A and B tubules
    • basal body
    • doublets 
    • a new organelle is regenerated as an outgrowth of the basal body
    • axoneme 
    • plus
  8. a.       intraflagellar transport
                                                                  i.      responsible for __; depends on activity of both __ along microtubules
    __ moves complex arrays of __, together with associated building materials, along __of the peripheral doublets to the assembly site at the tip of the growing __
    • assembling and maintaining these organelles
    • plus end- and minus end-directed movement
    • kinesin 2
    • IFT particles
    • protofilaments 
    • axoneme
  9. 1.       __ and __ are transported back toward the __ along the same __ by a __ mechanism 
    • kinesin 2 molecules and recycled axonemal proteins
    • basal body
    • flagellar microtubules
    • cytoplasmic dynein-powered mechanism
  10. a.       the dynein arms
                                                                  i.      the machinery for __ and __resides within the __
                                                                ii.      the protein responsible for conversion of the __ into __ was isolated by Gibbons
                                                              iii.      using various solutions capable of solubilizing different components, Gibbons carried out a chemical dissection of cilia from a protozoan
    ciliary and flagellar locomotion 


    chemical energy of ATP into the mechanical energy of ciliary location
  11. 1.       first: dissolved the enclosing plasma membrane in the detergent __
    a.       the __ of the insoluble fraction were then immersed in a solution containing __, a compound that binds and removes divalent ions
    When __ were examined in the electron microscope, what was missing?
    • digitonin
    • isolated axonenmes
    • EDTA
    • EDTA-treated axonemes
    • the central tubules were missing, as were the arms projecting from the A tubules
  12.                                                                                                                                       i.      simultaneous with the loss of these structures, the insoluble __lost their ability to __, while the __gained it
    1.       The __found in the __was a huge protein that he called __
    a.       now called __ to distinguish it from __, a related protein involved in organelle and particl etransport
    • axonemes 
    • hydrolyze ATP
    • supernatant 
    • ATPase
    • supernatant
    • dynein
    • ciliary dynein
    • cytoplasmic dynein
  13. 1.       when the insoluble parts of the __were mixed with the soluble protein int eh presence of Mg2+, much of the __activity once again became associated with the insoluble material in the mixture
                                                                                                                                        ii.      examination of the insoluble fraction showed that the __had reappeared on the__
    • axonmeme 
    • axonmeme 
    • arms 
    •  A tubules of the axonemes
  14. 1.       treatment of isolated sperm __with high salt would selectively remove the outer arms, leaving the inner arms in place
    a.       When __was added to __lacking outer arms, they beat at about half therate of the intact __, though they beat with a normal __
                                                                ii.      each dynein heavy chain is composed of a__, __ and __
    • axonemes 
    • ATP 
    • axonemes 
    • axoneme
    • waveform
    •  long stem, a wheel-shaped head, and a stalk
  15. a.       The mechanism of ciliary and flagellar locomotion
                                                                  i.      the contraction of muscle results from the __
    1.       the __ is generated by __ that reside in the head of the __molecule
    a.       with the muscle system as a model, it was proposed that ciliary movement could be explained by the __ relative to one another
    • sliding of actin filaments over adjacent myosin filaments
    • sliding force
    • ratchet-like cross-bridges
    • myosin 
    • sliding of adjacent microtubular doublets
  16.                                                               i.      in the intact __, the stem of each __ (with its associated intermediate and light chains) is tightly anchored to the outer surface of the __, with the __ and __ projecting toward the __ of the neighboring doublet
    • axoneme
    • dynein molecule
    • A tubule
    • globular heads and stalks
    • B tubule
  17. Explain the cilia movement in the example: 1 and 2
    • a.       dynein arms anchored along the A tubule of the lower doublet attach to the binding sites on the B tubule of the upper doublet
    • b.      the dynein molecules undergo a conformational change, or power stroke, that causes the lower doublet to slide toward the basal end of the upper doublet
  18. Explain the cilia movement in the example
    3 and 4
    • a.       the dynein arms have detached from the B tubule of the upper doublet
    • b.      the arms have reattached to the upper doublet so that another cycle can begin
  19.                                                               i.      __is an elastic protein that connects adjacent doublets
    1.       these __ play an important role in __ by limiting the extent that what?
    a.       the resistnacne to sliding provided by the __ causes the axoneme to bind in response to the sliding force
    • nexin 
    • nexin bridges
    • ciliary/ flagellar movement
    • adjacent doublets can slide over one another
    • nexin bridges
  20.                                                                                                                                       i.      sliding on one side of the axoneme alternates with sliding on the other side so that what happens?
    1.       this requires that, at any given time, the dynein arms on one side of the axoneme are __, while those on the other side are __
    • a part of the cilium or flagellum bends first in one direction and then in the opposite direction
    • active
    • inactive
  21. a.       as a result of this difference in dynein activity, the doublets on the inner side of the bend do what
    extend beyond those on the opposite side of the axoneme