Final Notes 1

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Final Notes 1
2013-11-23 17:21:39
Cell Bio

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  1. What are the three components of the cytoskeleton?
    - name one thing about them
    • microtubules: involved in cell division and plant cell wall
    • microfilaments: major function is muscle contraction
    • intermediate filaments: made of different kinds of proteins
  2. Which two cytoskeletal elements are involved in movement?
    It may not be the __. There are various types of movements.
    • microtubules and microfilaments
    • whole cell movement
  3. All cells have some sort of __; more extensive in __.
    • cytoskeleton
    • animal cells
  4. History of microtubules
    • not much known until the TEM
    • -some techniques (osmotetroxide) caused them to not be seen, but with gluteraldehyde, they were more visible

    With a light microscope, you aren't really seeing where they are; not specific
  5. Microtubules are components of almost all __ and at least __.

    Scientist at Boston College wrote a paper about it= __ (1960s; she pushed __)
    --- at first, it was proposed (not by her initially) for chloroplasts and she supported it in the 1960s.
    • all euk. cells
    • one prokaryote
    • Lynn Margulis
    • endosymbiosis
  6. The species Margulis saw microtubules in was a __.She said this was the __ in eukaryotes through some sort of __ that occured.

    There are actually __ (other than eukaryotes) with microtubules.
    • spirochete (a larger bacteria)
    • origin of microtubules
    • symbiotic relation
  7. What are the associations of microtubules? (fxn)
    • 1) motility (principle structure in euk. flagella and cilia)
    • 2) cell shape and division
    • 3) morphogenesis in plant cells
  8. Structures of microtubues

    Length and examples
    • straight, longitudinal, not really rigid nor flexible
    • unbranched

    • depends on function
    • ex: axons of nerve cells (10-25 micrometers)
    • cilia and flagella (5-200 micrometers)
  9. Another feature (varies) are the __. Not made from the same kind of __ and can differ.
    - __ can vary in __ as well.

    Function: ??
    • side arms
    • arms
    • proteins

    cross bridges
  10. When acting as cross bridges, what can the side arms be attached to?
    - another MT: if connected, less flexibility; more rigid; contributes to the stability of microtubues

    - can attack the microtubule to the PM, ER, etc. 

    - vesicles where they act as a tract and move vesicles along
  11. If the side arm is bound to MT, it __. 

    Arms contribute to the way that the MT __. 
    - they may have __. 
    Why were microtubules first discovered?
    • makes up a small percentage of it
    • associate with each other
    • ATPase
    • because they are larger
  12. Function of MT
    • cell shape
    • motion and movement: cilia and flagella
    • role in morphogenesis: affiliated with new cell wall material and orientation
  13. How can you find out if microtubules are involved in movement?
    • introduce an environment to depolymerize the MTs and see if it stops; if it does, then the MT are involved
    • or look at the cells to see if the MT are present in the area
  14. Cytoskeletal cell shape
    example 1: __.
    Orientation: __
    If put in __, what happens?
    • neurons
    • parallel to the long axis of the axon, which have alot
    • colchicine
    • the axons and shape get lost; they retract
  15. Cytoskeletal cell shape
    example 2: __.
    Orientation: __
    -Function of the structure mentioned in orientation
    • RBC in some fish and amphibians
    • MT at the edge of the cell are called marginal bands
    • - marginal bands are responsibel for keeping the cells in proper shape; they are very stable and not in mammalian BCs
  16. Movement 
    - four types
    • centrioles
    • cilia/ flagella
    • mitosis
    • rapid transport
  17. Centrioles
    Location: ?
    • animal cells, not in a typical plant cell 
    • if its in a plant cell, its rare
    • algae
  18. Centriole
    • pairs (in non-dividing cell, one pair)
    • - right angles to each other
    • - cylindrical
    • ---LENGTH: right at the edge of resolution (2000 Angstrom-4000 Angstroms long)

    centrioles never touch each other; between them is a fibrillar protein to hold them togeter

    surrounded by PCM
  19. Appearance of centrioles
    - major component: __
    - occurs in __
    - explain A, B, and C
    - membrane
    • MTs
    • nine groups, each containing three MTs
    • - there are none in the enter= 9+0 
    • A is complete with all subunits 
    • B and C are incomplete and share the subunits with A
    • no membrane to hold them together; protein holds the triplets together
  20. Duplication
    - arises from?
    - what doesn't happen?
    • - arises from preexisting centrioles; separate and give rise to a preexisting one
    • -do not touch; new one doesn't touch the parent one
    • -procentrioles (little buds that come off of it) [parent acts as a MTOC]
  21. What happens in plant cells in terms of MTs?
    - what you begin with
    - what forms
    - what's in the granula looking mass?
    • centrioles are needed for flagella
    • - what you begin with is a granular, amorphous material (deuterosome)
    • - what forms around the endge are centrioles
    • - tubulin and dimers; centrioles grow; granular molecule shrinks
  22. Function of centrioles
    • basic: help form the spindle
    • no connection between centrioles and the mitotic spindle
  23. Suggestions as to why there are centrioles at either pole
    • 1) centioles may bot be directly involved, but help recruit material from the PCM
    • 2) it guarantees that each daughter gets a pair of centrioles
  24. Centrioles may help __, but also help ensure that __.
    • recruit PCM
    • each daughter cell has one
  25. Centrioles act as a __ to form flagella; form __. 
    - Centrioles required to make sure they have an __. 
    - WIthout a __, you don't have cilia nor flagella. 
    Centrioles have nothing to do with the microtubules unless what?
    • MTOC
    • motor flagella
    • organized flagellum
    • Basal body
    • they are making proper material
  26. Cilia and Flagella: structure on bacteria
    cylindrical extensions from the surface of the cell; lining it is a bacterial enzyme
  27. What do they differ in? (they= cilia and flagella)
    beating pattern; quantity; length
  28. How many of each flagella and clila

    Major internal composition of these are __.
    • f: a few (1,2 or 4, but the average is two)
    • c: a ton
    • microtubules
  29. What happens in the axoneme in terms of movement?
    • the dynein arms are involved; they move; the doublets are moving relative to one another; A+B do not move as separate things; they move together; relative to the other subunit that's adjacent to it
    • dynein walks along the adjacent doublet