Vet histology reading pgs 32-64

  1. 3 main types of filaments in the cell? which is the most stable
    • Actin
    • microtubules
    • Intermediate filaments

    INtermediate filaments
  2. although there are tonnes of proteins making up intermediate filaments, name 4 particularly important groups
    • Keratins
    • Vimentin
    • Neurofilament
    • Lamins
  3. the accumulation of keratins (cytokeratins) is reffered to as? it most often happens where?
    • Keratanization
    • outside ofr epithelial cells
  4. Which intermediate filament protein class is the most common? Name two proteins in this class
    • Vimentin
    • Desmin
    • Glial fibrilar acidic protein (GFAP)
  5. What is the intermediate protein group that is found in major connections in neurons
  6. Where do we find lamins?
    Within the cell nuc;leus, forming the nucleuar lamina (just inside the nuclear envelope)
  7. Are inclusions enclosed by a membrane? What distinguishes them from an organelle?
    • No
    • No metabolic activity
  8. Give 4 good examples of common inclusions in cells
    • Fat droplets
    • Glycogen granules - Aggregate of carb polymer
    • Lipofuscin - the wear and tear pigment yellowish brown
    • Hemosiderin - often derived from phagocytosis of red blood cells, dense brown aggregate of denatured ferritin proteins with iron atoms bound
  9. Ribosomes are formed of?
    rRNA and many proteins
  10. The surface of the rough ER is basophilic/acidophilic and has what on its surface?
    • Basophilic because of protein production and all the phosphates in the area
    • ribosomes
  11. What does the Golgi do?
    Furhter processes proteins made in the RER
  12. What are the 2 faces of the golgi
    • Cis where they enter
    • trans where they leave
  13. What is autophagy
    When lysosomes fuse with old useless organelles to destroy them
  14. Differentiate between a primary lysosome and a secondary lysosome. What about a residual body?
    • Primary is essentially a fresh non fused lysosome with unused chemicals
    • Secondary has already fused with a vesicle and started working
    • Residual body is whats left and undigested after a lysosome is done all of its work on the vessicle
  15. describe the 2 mitochondrial membranes
    • outer = porous and encloses intermediate space
    • inner = very folded encloses gel like matrix
  16. Electron transport chain occurs on which membrane of mitochondria
  17. when do mitochondria release cytochrome c and what does it do
    • When stressed
    • apoptosis
  18. What do proteasomes do?
    Degrade improperly folded proteins after being tagged with ubiquitin
  19. WHat are in peroxisomes
    Enzymes for oxidation and detoxification, also catalase to break diown H2O2
  20. Describe what microtubules look like
    semirigid tubular structures
  21. Whats bigger microtubules or actin
    MIcrotubules are biggest then intermediate then actin is the smallest (often reffered to as microfilaments
  22. What are 2 good uses for microtubules
    Maintaining cell shape and trcks for transport of vesicles by motor protein kinases
  23. Which cytoskeletal filament is most responsible for movement
  24. What are the motor proteins that work on actin
  25. Which of the cytoskeletal filaments is the most stable and almost purely for structure
    intermediate filaments
  26. What is typically the largest structure within a cell
  27. 3 main structures of the nucleus
    • Nuclear envelope
    • chromatin
    • nucleolus
  28. Describe the nuclear envelope
    • 2 membranes, inbetween is perinuclear space
    • outer membrane is contuous with the RER
    • inner membrane is continuous with the nuclear lamina which stabilizes the envelope
  29. What connects the two nuclear membranes and allows transfer between the inside and outside of the nucleus , what is the main component making it up
    • nuclear pore complexes
    • nucleoporins
  30. can ions move through nuclear pore complexes?
    Yes but larger molecules are regulated both ways
  31. What is chromatin
    Combination of DNA and its associated proteins
  32. What is chromatin active in transcription called? what about inactive? What colour do they stain?
    • Euchromatin - light
    • heterochromatin - dark
  33. to pack DNA in the chromatin it is wrapped around what structure? This forms a what? Are chromatin condensed in any other ways?
    • Histones
    • nucleosone
    • Yes but less understood, involves other proteins including complexes of condensins
  34. What is the part of chromatin where rRNA transcription and ribosomal sub unit assembly occur called? basophilic/acidophilic?
    • nucleolus
    • basophilic, it is very electron dense
  35. What is the cell cycle?
    Sequence of events that controls cell growth and division
  36. What is the longest phase of the cell cycle
    G1 includes all preparation for DNA replication and occurs right after mitosis
  37. What comes after G1 phase?
    S phase or phase of DNA and histone synthesis
  38. G2 phase what occurs?
    • Cell prepares for division through mitosis
    • ex) accumulate proteins needed for division
  39. What cytoplasmic proteins control the cell cycle? What do they bind too?
    • cyclins
    • cyclin dependants kinases
  40. WHat do CDKs (cyclin dependant kinases) do?
    phosphorylate and activate enzymes and transcription factors whos functions characterize each cycle
  41. When do the cyclins of each phase change?
    • Only once all activites of a phase are complete and the cell is ready to move onto the next phase
    • at this point proteasomes eat up the previous cyclin and the new one takes over
  42. What is the G1 restriction point
    one of many slow down restriction points where problems that may have occurred with DNA during growth or replication is fixed so that problems do not occur further
  43. What are the 4 phases of mitosis and what occurs during them
    • Prophase - chrom condense, envelope dissolves, microtubular spindles form
    • metaphase - chromosomes align
    • anaphase - when chromes separate towards two centrosomes
    • telophase - nuclear envelope reforms around separated chromsomes
  44. Telophase ends with what? What filaments are responsible for this? What organ uses this same system for contraction?
    • cytokinesis or cell cleavage
    • contractile ring of actin and myosin
  45. So when does cytokinesis occur?
    It is essentially the last section of telophase
  46. What are kinetochores?
    Large protein complexes on the mitotic spindle that the chromosomes attach too
  47. What is the name for the combination of G1 S and G2 phase
  48. What signals from the environment activate cell cycling?
    mitogens or growth factors
  49. What is the function of the Golgi?
    Further process proteins made in the rough ER as well as package for secretion and other roles
  50. The Golgi is made of stacked membranous?
  51. The Golgi has 2 faces describe each. it also has an area for enzymatic modification what are these called?
    • cis = vesicle receiving
    • trans = vesicle releasing
    • medical cisternae
  52. What are the names of the proteins that guide vesicles through the golgi
    coat proteins COP1 and COP2
  53. What are 2 important protein modifications that occur in the Golgi?
    • sulfation
    • glycosylation
  54. Modified proteins leave the Golgi in what? how do they direct their movement? Where are 3 places they could go?
    • vessicles
    • coat proteins
    • lysosomes, plasma membrane, exocytosis
  55. Define a primary lysosome vs a secondary lysosome?
    • primary leaves the Golgi containing inactive acid hydralases
    • secondary are much more variable having fused with vesicles from endocytosis and having digested the contents
  56. Define autophagy?
    Lysosomes digesting uneeded or non-functional organelles by fusing with their membranes
  57. Where do the products of secondary lysososme digestion go? If the material stays in a vesicle what is it then called?
    • Into the cytoplasm to be re used
    • residual bodies
  58. What is a proteasome?
    Small cytoplasmic protein complex that degrades improperly folded proteins after being tagged with ubiquitin
  59. Main function of mitochondria?
    ATP synthesis
  60. How do mitochondria reproduce?
    • Fission of older mitochondria
    • like bacteria
  61. 2 membranes of mitochondria? Whats inbetween them?
    • porous outer membrane
    • inner membrane (with all the folds)
    • intermembrane space
  62. Enzymes found in the mitochondrial matrix are used for what processes?
    • beta oxidation
    • citric acid cycle
  63. Where in the mitochondria does the electron transport chain happen?
    On the inner membrane
  64. Stressed cells can release what from the mitochondria to cause apoptosis? what part of the mitochondria does it come from?
    • Cytochrome C
    • inner membrane
  65. What is a peroxisome? What is found in it? What is its function
    • small spherical organelle containing enzyme
    • enzymes for metabolic reactions, oxidation and detoxification as well as catalase to break down H2O2 resulting from the earlier stated reactions
  66. 3 types of polymers found in the cytoskeleton?
    • microtubules
    • microfilaments (actin)
    • intermediate filaments
  67. Describe the structure of microtubules
    semirigid tubular structure made of polymerized tubulin heterodimers
  68. What makes up microtubules
    polymerized tubulin heterodimers
  69. What are 2 functions of microtubules
    • maintaining cell shape
    • tracks for transport
  70. What are the 2 proteins used to transport vesicles and organelles along the microtubules?
    • motor protein kinesin
    • dynein
  71. What are the motor proteins that move along with actin?
  72. 3 things actin contraction and movement is important for in the cell?
    • endocytosis
    • cell cleavage
    • mitosis
  73.  intermediate filaments are composed of various protein subunits which vary within different cells, what are 4 of them?
    • vimentin
    • lamins
    • neurofilament proteins
    • keratins
  74. What are inclusions?
    Non metabolically active  storage sites
  75. Differentiate in movement between COP 1 and COP 2
    COP 1 moves retrograde and COP 2 moves forward
  76. What is a zymogen granule?
    secretory granule with dense contents of digestive enzymes
  77. What is a heterolysosome?
    Lysosome after ingesting something to digest
  78. What is ubuiquitin
    protein that helps lead misfolded proteins to their death
  79. The mitochondria innermembrane has infoldings called?
  80. What is a large organized congregation of microtubules called?
  81. What are the subunits of the microtubule
    alpha and beta tubulin
  82. What creates microtubules?
    Microtubule organizing centers
  83. What is meant when said that microtubules show dynamic instability? The rate of this based on the concentration of what 4 things?
    They are contantly polymerizing an depolymerizing at a constant rate

    • Tubulin
    • Ca
    • Mg
    • and Microtubule associated proteins (MAPs)
  84. What is the dominant MIcrotubule organizing center in most cells? What is it made up of?
    • Centrosome
    • 2 centrioles at right angles to eachother
  85. What is meant by actin treadmilling
    The fact that one end of actin is always being added to and the negative end is always being dissociated and therefore actin is very dynamic in its movement and a monomer moves from end to the other like being on a treadmill
  86. What is a stress fiber?
    Cells attached to firm substrates actin filaments can get concentrated into parralell bundles called stress fibers
  87. What is a barr body?
    Sex chromosome
  88. What is a karyotype
    the collection image of an individuals chromosomnes
  89. What is a cyclin?
    cytoplasmic proteins that regulate cell cycling
  90. What are mitogens?
    Postmitotic protein signals that activate cell cycling
  91. What is interphase?
    Combination of G1, G2 S phase
  92. What serves as a site for attachment of microtubules on the chromosome?
    A large protein complex called the kinetochore
  93. What is synapsis?
    Where homologous chromsomes of each pair come together
  94. Crossover is when?
    Their is reciprocal DNA exchange between aligned maternal and paternal chromsomes
  95. What is a pyknotic nuclei?
    dense darkly stained blobs in a dying apopotic cell
Card Set
Vet histology reading pgs 32-64
Vet histology reading pgs 32-64