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2011-09-17 23:17:58
Cells Part2

Cells Part 2
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  1. Can be divided into cytosol, cytoplasmic organelles and inclusion bodies (non-living accumulations of material ie lipid droplets)
  2. Intracellular fluid
  3. What percentage of cytosol is water with other components?
  4. What percentage of the cell volume is the cytosol?
  5. What components can you find in the cytosol?
    • Large organic molecules (proteins, carbos, lipids)
    • Small organic molecules (simple sugars and ions)
  6. Site of many important chemical reactions
    -production of ATP, synthesis of building blocks
  7. What are they?
    Membranous organelles surrounded by one or two lipid bilayer membranes - help separate functions
    Some are non-membranous and are in direct contract with cytoplasm
    Cell Organelles
  8. Large organelle with double membrane nuclear envelope
    Outer membrane is continuous with rough ER
    Perforated by water-filled nuclear pores
  9. Why are there water-filled nuclear pores on the nucleus?
    To allow active transport of large proteins and ribosomes
  10. Spherical, dark bodies within the nucleus (no membrane)
  11. Site of ribosome assembly
  12. Where are genes found?
    On Chromosomes
  13. What are genes?
    Directions for a specific protein
  14. What do non-dividing cells contain?
    • Nuclear chromatin
    • -loosely packed DNA
  15. What do dividing cells contain?
  16. What do chromosomes contain?
    Tightly packed DNA
  17. What does it mean that some cells are anucleate? (eg RBC's)
  18. What does it mean that some cells are multi-nucleate? (eg skeletal muscle)
  19. What do free ribosomes do?
    They are loose in the cytosol to synthesize proteins found inside the cell
  20. What are membrane-bound ribosomes attached to?
    Attached to endoplasmic reticulum (ER) or nuclear membrane
  21. What synthesizes proteins needed for plasma membrane or for export?
    Membrane-bound ribosomes
  22. What is transciption?
    Transcribe DNA information onto a messenger RNA molecule (mRNA)
  23. What is translation?
    the mRNA translates the "message" into a sequence of amino acids in order to build a protein molecule
  24. What type of RNA carries amino acids to ribosomal RNA (rRNA) for protein synthesis?
    Transfer RNA (tRNA)
  25. True or false: Amino acids = protein
  26. Network of membranes forming flattened sacs or tubules called cisterns
    Endoplasmic Reticulum
  27. Continuous with nuclear envelope and covered with attached ribosomes
    Synthesizes, processes and packages proteins for export
    Rough ER
  28. Synthesizes phopholipids, steroids and fats
    Detoxifies harmful substances (alcohol)
    Calcium storage in muscle cells
    Smooth ER
  29. Comprised of 3-20 flattened, curved membranous saces called cisterns
    Golgi Complex
  30. Which side of the Golgi Complex faces the ER? Convex or concave
    • Convex side faces ER
    • Concave side faces cell membrane
  31. Processess and packages proteins produced by rough ER
    Golgi Complex
  32. How to proteins pass from rough ER to golgi complex?
    via transport vesicles
  33. What are the three cisterns of the Golgi Complex?
    Processed proteins pass from entry cistern to medial cistern to exit cistern in transfer vesicle
  34. What types of vesicles do finished proteins exit golgi as?
    • Secretory
    • Membrane or
    • Storage Vesicle (lysosome)
  35. Membranous vesicles
    Formed in Golgi complex
    Filled with digestive enzymes
  36. Digests foreign substances
    Recycles own organelles
  37. Membranous vesicles that:
    Smaller than lysosomes
    Contain enzymes that oxidize organic material
  38. Part of normal metabolic breakdown of amino acids, fatty acids and free radicals
    Oxidizes toxic substances such as alcohol and formaldehyde, usually found in the liver and kidneys
  39. Very small vesicles that contain proteases for digestion of proteins
  40. Double membrane organelle
    Central cavity known as matrix
    Inner membrane folds known as crista
  41. Generation of ATP
    Powerhouse of cell
  42. This increases with need for ATP
    Mitchondria self-replication
  43. Network of protein filaments throughout the cytosol
  44. Cell support and shape
    Organization of chemical reactions
    Cell and organelle movement
  45. Thinnest filaments (actin) in the cytoskeleton
    Locomotion and division
    Support microvilli
  46. Several different proteins
    Anchor organelles
    Strengthen and shape
    Intermediate Filaments
  47. Large clindrical structures composed of tubulin
    Flagella, cilia, and centrosomes
    Play a role in transport
  48. Motile projections of cell
    Bundles of Microtubules
    Cilia and Flagella
  49. State the two differences between cilia & flagella
    • Cilia: short and multiple
    • Flagella: longer and single
  50. Found near nucleus
    2 Centrioles (90 degrees to eachother)
    Consist of bundle of microtubules
  51. Role in formation of cilia and flagella
    Formation site for mitotic spindle and microtubules
  52. Aggregates of non-living organic molecules in the cytosol
    Diverse in composition, shape and longevity
    Examples include granules of melanin (in skin), glycogen (in liver) and lipid droplets (in fat cells)
    Cytoplasmic Inclusions
  53. 4 Theories to explain aging:
    • 1. Cells have limited number of divisions
    • 2. Autoimmune responses due to changes in cell identity markers
    • 3. Free radical theory (electrically charged moleculres with an unpaired electron cause cell damage, more metabolism more free radicals)
    • 4. Genetic telomere theory
  54. theory of aging: structures on ends of chromosomes get closer as DNA replicates (some nucleotides lost) and eventually stop replicating. Telomerase prevents telomeres from degrading by adding more repeating DNA-used in cell cultures, endless replication observed, called immortality enzyme
    Genetic telomere theory
  55. Increased number of cell division
  56. True or false: a benign tumor does not metastisize or spread.
  57. Spreads due to cells that detach from tumor and enter blood or lymph
  58. Causes of cancer
    Carcinogens, x-rays, viruses
  59. Why is there cancer?
    • Every cell has genes that regulate growth and development
    • Mutation in those genes due to radiation or chemical agents causes excess production of growth factors
  60. What are the five functions of proteins?
    • 1. Transport
    • 2. Communication
    • 3. Tissue formation
    • 4. Enzymatic reactions
    • 5. cell identification