1. functions of intermediate filaments
    provide tensile and mechanical strength
  2. functions of microtubules
    cell organization and division
  3. functions of actin filaments
  4. myosins
    molecular motors required for muscle contractions and other functions
  5. kinesins
    molecular motors associated with microtubules - move cargo toward the plus end
  6. dyneins
    molecular motors associated with microtubules - usually move cargo toward the minus end
  7. keratins
    cytoplasmic intermediate filaments - epithelial
  8. vimentins
    cytoplasmic intermediate filaments - in connective tissue and muscle and neuroglia
  9. neurofilaments
    cytoplasmic intermediate filaments - in nerve cells
  10. nuclear lamins
    nuclear intermediate filaments - in all nucleated cells
  11. structure of intermediate filaments
    two conserved alpha-helical monomers form a coiled-coil dimer; two dimers form a staggered tetramer; eight tetramers twist into a ropelike filament; globular heads vary in shape and size
  12. structure of microtubules
    hollow cylinders made of the protein tubulin - a dimer formed from alpha and beta tubulin associated with 2 GTP; grow from centrally located centrosome in cytoplasm of cell
  13. structure of actin filaments
    two-stranded helical polymers of the protein actin; have structurally unique plus and minus ends
  14. classes of actin binding proteins
    monomer sequestering proteins; nucleating proteins; bundling proteins; motor proteins; side-binding proteins; capping proteins; severing proteins; cross-linking proteins
  15. monomer sequestering proteins
    interact with actin monomers to prevent them from assembling
  16. nucleating proteins
    interact with actin to facilitate the addition of subunits at the plus end
  17. bundling proteins
    bundle actin filaments to make larger and stiffer structures
  18. motor proteins
    myosins - interact with actin to produce movement
  19. side-binding proteins
    selectively stabilize actin filaments
  20. capping proteins
    prevent further addition of subunits at the plus or minus end of actin filaments
  21. severing proteins
    fragment actin filaments to increase fluidity
  22. cross-linking proteins
    hold actin filaments together in a gel-like meshwork within the cell cortex
  23. power stroke
    occurs as myosin head pivots; causes motion of actin filament
  24. action of myosin motors
    ATP binding causes myosin head dissociation; ATP is hydrolyzed to ADP and phosphate; power stroke due to conformational change of the myosin head is triggered by the release of phosphate
  25. mechanism of directed cell migration
    involves polarized assembly of actin based machinery; localized cell adhesion; actin-based membrane protrusion at the leading edge to produce lamellipodium; actin-myosin interaction at the tail
  26. colchicine-derived drugs
    bind to free tubulin and prevent their polymerization into microtubules; stalls cell in mitosis
  27. taxols
    bind to microtubules to prevent them from losing subunits; stalls cell in mitosis
  28. axonal microtubule polarity
    plus ends of microtubules are distal to the cell body
  29. dendritic microtubule polarity
    polarity of microtubules is mixed
  30. microtubule organizing centers
  31. tubulin
    a protein dimer composed of alpha and beta tubulin
  32. protofilaments
    strands of tubulin dimers
  33. energy source in microtubules
    GTP bound to subunits of tubulin
  34. centrosome
    the microtubule organizing center; typically located close to the cell nucleus
  35. centriole
    structures found in the centrosome; made up of a cylindrical array of short microtubules
  36. dynamic instability
    the process of alternating microtubule growth and shrinkage
  37. MAPs
    microtubule-associated proteins; regulate microtubule assembly and stability
  38. gamma-tubulin ring complexes
    nucleation sites for microtubule growth; ring-shaped
  39. primary cilium
    a signaling structure found in every differentiated cell
  40. roles of cilia
    motility; sensory
  41. axoneme
    a microtubule-based cytoskeletal structure found inside cilia
  42. basal body
    a specialized centriole; anchors cilia
  43. ciliary membrane
    extends from the plasma membrane
  44. anaphase A
    the stage in mitosis during which chromatids separate; kinetochore mucrotubules shorten by depolymerization
  45. anaphase B
    the stage in mitosis during which the spindle poles move apart; kinesins and dyneins act on overlapping microtubules and astral microtubules
  46. kinetochore
    the paired protein structure to which centrosomes attach; responsible for spindle assembly and regulation of microtubule dynamics and separation of chromosomes
  47. overlapping microtubules
    overlap in the center of the cell; involved in anaphase B; push spindle poles apart
  48. astral microtubules
    radiate outward from centrosomes; involved in anaphase B
  49. tubulin flux
    "a constant slow flux of microtubules in the spindle; ""treadmilling"""
  50. proposed mechanisms for kinetochore microtubule shortening
    ATP motor protein driven? Microtubule disassembly driven?
  51. desmosomes
    cell-cell spot adhesions formed by interactions between cadherins and intermediate filaments
  52. hemidesmosomes
    cell-extracellular matrix spot adhesions formed by interactions between integrins and intermediate filaments
  53. actin-myosin interactions
    myosin moves toward the plus end of actin filaments
  54. structure of myosin
    head and neck and tail regions; head region = motor domain
  55. mechanism of cilia and flagella movement
    dynein-driven microtubule sliding
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