Card Set Information

2011-09-16 22:23:12
Cells part

Cells Part 1
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  1. Basic, living, structural and functional unit of the body
    Cellular Level
  2. Level with compartmentalization of chemical reactions within specialized structures
    Cellular Level
  3. Another name for the Cell membrane
    Plasma membrane
  4. Genetic material of a cell
  5. everything between the membrane and the nucleus
  6. Name for the intracellular fluid in the cytoplasm
  7. Name for the subcellular structures with specific functions (in the cytoplasm)
  8. Flexible but sturdy barrier that surrounds cytoplasm of cell and separates the external and internal environments of the cell
    Plasma Membrane
  9. Important for regulating the movement of substances into and out of the cell
    selective permeability
  10. Important for communication with other cells and substances
    plasma membrane
  11. True or false: most cells have a common overall structure
  12. What does the plasma membrane consist of?
    • lipids
    • proteins
    • carbohydrates
  13. What model describes the structure of the plasma membrane?
    Fluid mosaic model
  14. Describe the fluid mosaic model
    • Sea of lipids in which proteins float like icebergs
    • lipid is barrier to entry or exit of polar substances
    • proteins are "gatekeepers" -- regulate traffic
    • carbohydrates provide attachment points and protection
  15. Comprises most of the lipids
  16. 2 parallel layers of phospholipid molecules
    phospholipid bilayer
  17. True or false: Polar parts (heads) of phospholipids are hyrophobic
    • False.
    • Polar parts (heads) are hydrophilic and face on both surfaces of a watery environment
  18. True or false: nonpolar parts (heads) are hydrophobic
    • True.
    • Nonpolar parts line up next to each other in the interior
  19. Where do carbohydrate groups attach to the cell membrane?
    Carbohydrate groups attach to the polar heads on hte side of the membrane facing the extracellular fluid
  20. What are carbohydrate groups important?
    They are important for cell adhesion and cell recognition (forms part of the glocoalyx-protective sugar coating)
  21. Where can you find cholesterol in the cell membrane?
    Interspersed among the other lipids in both layers
  22. Why is cholesterol important within the cell membrane?
    Important for strengthening the cell membrane and making it flexible.
  23. What are they?
    Usually extend completely across the cell membrane
    Form a small protein channel for transport of substances
    Integral Proteins
  24. What are they?
    Attached to either inner or outer surface cell membrane and are easily removved from it
    Peripheral proteins
  25. What are they?
    Sugars attached to proteins
  26. Why are glycoproteins important? (3 reasons)
    • Have the sugar portion facing the extracellular fluid to form a glycocalyx
    • Gives cell "uniqueness", protects it from being digested
    • Creates a stickiness to hold it to other cells and forms part of a glycocalyx
  27. Which Membrane Proteins:
    Name for the passageway to allow specific substance to pass through (especially non-liped soluble substane)
  28. Which Membrane Proteins:
    Binds a specific substance, changes their shape and movies it across the membrane
    Transporter Proteins
  29. Which Membrane Proteins:
    Cellular recognition site
    Binds to substance
    Receptor Proteins
  30. Which Membrane Proteins:
    Allows cell to recognize other similar cells
    Cell Identity Marker
  31. Which Membrane Proteins:
    Anchor proteins in cell membrane or to other cells
    Cell shape and structure
  32. Which Membrane Proteins:
    Speed up reactions
    Act as Enzyme
  33. Permeable to nonplar, uncharged molecules -- oxygen, CO2, steroids
    Permeable to water which flows through gaps that form in hydrophobic core of membrane as phospholipids move about
    Lipid bilayer (selective permeability)
  34. True or false: Transmembrane proteins act as specific channels.
    True, for small and medium polar & charged particles
  35. How do macromolecules pass through the membrane?
    Vesicular transport
  36. Moves substances down their concentration gradietn with only their kinetic energy
    Passive Transport
  37. Uses ATP to drive substances against their concentration gradient or to move large molecules across the membrane
    Active Transport
  38. What are the principles of diffusion?
    • 1. Random mixing of particles in a solution as a result of the particle's kinetic energy
    • ----aka more molecules move away from an area of high concentration to an area of low concentration
    • 2. when the molecules are evenly distributed, equilibrium has been reached
  39. Why is diffusion important?
    Important for absorption of nutrients and excretion of wastes
  40. What type of molecules diffuse?
    • Nonpolar, hydrophobic molecules:
    • oxygen, carbon dioxide, nitrogen, fatty acids, steroids, small alcohols, ammonia and fat-soluble vitamins (A, E, D and K)
  41. Which type of transport across the plasma membrane:
    1. Substance binds to specific transporter protein
    2. Tranporter protein moves substance across cell membrane.
    3. Only occurs down concentration gradient --if no concentration difference exists, no net movement occurs
    Facilitated Diffusion
  42. Explain how glucose would enter a cell
    • 1.Glucose binds to transport protein
    • 2.Transport protein changes shape
    • 3. Glucose moves across cell membrane (only down concentration gradient)
  43. Net movement of water through a selectively permeable membrant from an area of high water concentration to an area of lower water concentration
    --diffusion through lipid bilayer
  44. What type of solution:
    Water concentration the same inside and outside of cell results in no net movement of water across the cell membrane
    Isotonic Solution
  45. What type of solution:
    Higher concentration of water ouside of cell reults in hemolysis
    Hypotonic Solution
  46. What type of solution:
    Lower concentration of water outside of cell cause crenation
    Hypertonic Solution
  47. A process in which substances move across a plasma membrane down a pressure gradient
  48. Movement of charged substances, large substances and nonlipid substances against their concentration gradient mainly through protein channels
    -energy-requiring process (energy from hydrolysis of ATP)
    Active Tranport
  49. Examples of actively transported molecules
    Na+, K+, H+, Ca+2, I-, Cl-, amino acids and monosaccharides
  50. Vesicular Transport:
    Bringing something into a cell
  51. Cell eating by macrophages & WBC
    (whole bacteria or viruses are engulfed and later digested)
  52. Cell drinking
  53. Selective input
    Substance binds to receptor on cell membrane before being ingested (ie hormones)
    Receptor-mediated endocytosis
  54. Release something from cell
    -Vesicles form inside cell, fuse to cell membrance
    -Release their contents
  55. What do vesicles release from exocytosis?
    • Digestive enzymes
    • hormones
    • neurotransmitters or
    • waste products
  56. What is the difference between pinocytosis and phagocytosis in regards to structure:
    • Pinocytosis: no pseudopods form & nonselective drinking of extracellular fluid
    • Phagocytosis: pseudopods extend to form phagosome & lysosome joins it
  57. Why is there receptor-mediated endocytosis?
    Mechanism for uptake of specific substances -- ligands
  58. Desired substance binds to receptor protein in clathrin-coated pit region of cell membrane causing membrane to fold inward
    Ligands are digested by lysosomal enzymes or transported across cell - epithelial cell crossing accomplished
    receptor-mediated endocytosis