Histo-Eukaryotic cell.txt

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Histo-Eukaryotic cell.txt
2014-11-11 16:06:59
histo cell

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  1. The membrane of a eukaryotic cell is ______and ______.
    thin and asymmetrical
  2. Membrane anatomy as revealed by the freeze-fracture technique?
    fluid-mosaic model, lipid bilayer i intersperse with proteins that act as channels through the membrane
  3. Lipid rafts are microdomains containing __(3)__ that form in the plane of the bilayer; they serve as sites for...
    cholesterol, sphingolipids, and membrane proteins; signaling across the plasma membrane
  4. Integral proteins in the cell membrane form _____ and penetrate __________ the lipid bilayer.
    hydrophobic bonds; partially or through
  5. Paramembrane proteins associate with ________ of the membrane and form _____ and _____.
    polar heads; H-bonds; ionic interactions
  6. Membrane performs 3 functions...
    selective permeability barrier, subdivide and compartmentalize cytoplasm (making organelles), transduce and transform signals into and out of the cell
  7. What are the 2 types of chromatin and their functions?
    Heterochromatin- very tightly coiled for storage; euchromatin- loose and light and actively being transcribed to RNA
  8. Structure that separates the nucleoplasm from the cytoplasm; has ribosomes attached to the cytoplasmic side.
    nuclear envelope
  9. What is the function of the pores of the nuclear envelope?
    permit selective passage of RNAs out of the nucleus and nuclear proteins into the nucleus
  10. How does the cell differentiate which proteins are permitted to enter the nucleus through pores in the nuclear envelope?
    nuclear proteins have nuclear localization signals
  11. The closely applied layer on the nucleoplasm side of the nuclear envelope that confers strength to the structure.
    fibrous lamina
  12. When are chromosomes visible?
    During mitosis only
  13. Chromatin consists of....
    DNA plus basic proteins called histones
  14. what cell has a nucleus packed with mostly heterchromatin?
    sperm cell
  15. what cell has a very prominent nucleolus?
    neuron (nerve cell)
  16. The bulk of the nucleolus is _____ because it is....
    RNA; the site of synthesis of cytoplasmic ribosomal RNA
  17. Ribosomes bind to the ____ of the rough ER to synthesize protein that will be...
    cisternae; secreted into the lumen of the ER or become membrane proteins
  18. Structure of the ribosome?
    two subunits: large 60S subunit and small 40S subunit
  19. When synthesizing cytoplasmic proteins for domestic use, how to ribosomes associate?
    ribosome, mRNA, tRNA, and enzymes associate freely in the cytoplasm
  20. What are the 3 functions of the smooth ER and where do these functions take place (organ)?
    biosynthesis of steroids (testis), drug detoxification (liver), calcium ion pumping and sequestration (muscle)
  21. What are the functions (3) of the Golgi apparatus and where is its function prominent (organ)?
    receives newly formed proteins from the ER, attaches sugars to make glycoproteins, and packages the proteins into secretion granules; prominent in the pancreas
  22. Describe the structure of the Golgi apparatus.
    convex forming face (receives vesicles from rough ER) and concave maturing face (buds off newly formed secretion granules)
  23. lysosomes have a __(2)__ membrane.
    single trilaminar, impermeable membrane
  24. Lysosomes contain _____.
    hydrolytic enzymes with acid pH optima
  25. Give an example of a hydrolytic enzyme in a lysosome.
    acid phosphatase
  26. What are the 2 functions of the lysosome?
    intracellular digestion of material ingested by phagocytosis or pinocytosis, digestion of internal cellular debris (autophagy)
  27. What diseases can be caused by lysosome malfunction?
    inflammatory diseases (caused by release of destructive lysosomal enzymes), such as Gout and rheumatoid arthritis, lysosomal storage diseases, such as Pompe's Disease, Tay-Sach's disease, Danon's Disease
  28. Peroxisomes, aka _____, are present in all cells of the body, except ____.
    microbodies; RBCs
  29. Spherical, membrane-bound organelles with a crystalline core.
  30. Peroxisomes have a _____ membrane and contain ______ and _____.
    permeable; catalase; oxidases
  31. What is a major function of peroxisomes?
    to break down hydrogen peroxide with catalase
  32. What disease is associated with peroxisome malfunction?
    X-ALD (accumulation of fatty acids on the brain)
  33. describe the structure of a mitochondrion.
    two concentric membrane-bound spaces
  34. What is the location of ATP synthesis in mitochondria?
    ATPase is attached to cristae of the inner membrane, exposed to the matrix
  35. Inner membrane spheres of a mitochondrion are involved with...
    coupling respiratory electron transport to the phosphorylation of ADP
  36. Where are mitochondria localized?
    near the site of energy utilization, such as sperm tail and muscle
  37. Mitochondria play an important role in the regulation of _____.
  38. Describe the mitochondrial DNA.
    small, circular, double-stranded
  39. Mitochondria grow and divide by ____.
    binary fission
  40. How did mitochondria originate?
    as aerobic prokaryotic endosymbionts (Rickettsia)
  41. The function of intermediate filaments of the cell?
    mechanical support and strength
  42. Keratin intermediate filaments are prominent in ______ cells.
  43. Desmin intermediate filaments is prominent in _____ cells. (3)
    Smooth, skeletal, and cardiac muscles
  44. Microfilament are also called _____.
    actin filaments
  45. Where in the cell are microfilaments most highly concentrated?
    in the cortex, just below the plasma membrane
  46. Microfilaments/actin filaments have what functions in the cell? (3)
    cell motility, organelle transport, and contraction
  47. What are the functions of myosin filaments? (2)
    contraction, vesicular transport
  48. The building block of microtubules is a __________ of two _________.
    heterodimer; tubulin monomers
  49. Where in the cell are microtubules concentrated?
    near the cell center, where the centrioles are
  50. Microtubules are components of what components of the cell? (5)
    flagella and cilia (axoneme), mitotic apparatus, cytoskeleton, saltatory movements, axoplasmic flow (movement of organelles and molecules within the cell)
  51. Each centriole is part of a _______ and is composed of _______.
    pairs; nine sets of triplet tubules
  52. Centrioles play a role in... (2)
    establish cell polarity for the spindle during cell division, direct assembly of a cilium
  53. A centriole engaged at the base of a cilium.
    basal body
  54. Glycogen, a cell inclusion, i a highly branched polymer of _____.
  55. The function of glycogen in a eukaryotic cell?
    carbohydrate energy store
  56. Lipid droplets, as inclusions, are prominent in _____ cells.
  57. Pigment granules that contain brown pigment call melanin.
  58. Pigment that accumulates in cell as they age (brown); prominent with cardiac cells.
  59. Iron-containing pigment formed from the breakdown of hemoglobin in the liver, spleen, and BM.
  60. Phase during which synthesis of RNA and protein takes place.
  61. The phase during which DNA replication and synthesis occurs.
    S phase
  62. Phase during which cells have polytene chromosomes and polyploid cells.
  63. Different types of chromosomes are identified according to the location of the _____ during ______.
    kinetochore; metaphase
  64. Orderly arrangement of homologous chromosomes characteristic to each species.
  65. Chromosomes are condensed by...
    making numerous loops on the protein scaffold.
  66. Phase of mitosis when the nucleus breaks up, the nucleoli disappear, and the centrioles polarize the cell to form the mitotic spindle.
  67. The phase of mitosis when microtubules insert into the kinetochore, and the chromosomes line up at the center of the cell.
  68. The phase of mitosis when sister chromatids travel to opposite ends of the cell.
  69. Homologous chromosome act ____ during mitosis.
  70. The phase of mitosis when the chromosomes uncoil and the nuclear envelopes reform, nucleoli reform, and the cytoplasm divides.
  71. What structures are involved in cytokinesis during telophase.
    actin and myosin filaments for the contractile ring
  72. During meiosis I, homologous chromosomes act ________.
    as a pair (synapsis)
  73. When does crossing over occur?
    Prophase I
  74. Example of a disease resulting from a meiotic abnormality.
    Down syndrome (trisomy 21)