Cell biology; Biology part 1

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Cell biology; Biology part 1
2012-02-16 14:02:16

biology first powerpoint part 1
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  1. Cell theory (4)
    -all living things are made of cells

    -cells contain all the basic units needed for life

    -all cells come from other cells

    -cells are small and tend to maximize their surface area
  2. Cells are microscopic because...
    as cell size increases, the surface area to volume ratio decreases

    -thus rates of chemical exchange may then be inadequate for cell size.
  3. Light microscopes
    refract visible light passing through a specimen such that projected image is magnified
  4. Electron microscope (EM)
    focuses a beam of electrons through the specimen
  5. 2 types of electron microscopes
    Transmission electron and scanning electron
  6. Scanning electron
    electron beam scans the surface of specimen.

    -image appears 3-D
  7. Transmission Electron
    a beam of electrons passed through a thin section of specimen stained with atoms of heavy metals and electromagnets
  8. Prokaryotes characteristics (5)
    -in nuceoid region

    -usually smaller

    -usually single-cell

    -may not need oxygen

    - no membrane-bound organelles
  9. Eurakaryotes characteristics (5)
    -within membrane bound nucleus

    -usually larger

    -often multicellular

    -usually need oxygen to exist

    -membrane-bound organelles
  10. Biological membranes
    -complex, dynamic structures made of lipid and proteing molecules

    • *communicates with other cells
    • *regulates passage of materials
    • *transmits signals between cell interior and the environment
  11. know parts!!
  12. Membranes are selectively permeable by...
    -Passive transport

    -active transport


  13. Passive transport
    -diffusion and Osmosis
  14. Active trasnport
    -channel proteins and carrier proteins
  15. Exocytosis
    movement of molecules out of cell using membrane fusion

    ex)removing cellular waste; exporting proteins
  16. Endocytosis
    movement of molecules into the cell using membrane fusion
  17. Diffusion
    net movement of a substance from a region of greater to lower concentration
  18. Hypotonic solution
    net water movement into the cell
  19. Hypertonic solution
    net water movement out of water
  20. Isotonic solution
    no net water movement