Life Science Chapter 2 The Cell

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Life Science Chapter 2 The Cell

  1. 1. Chapter 2The Cell
  2. 2. 2-1 Cells: The Units of Life
  3. 3. The Microscope: A ToolQ: Why do scientists need to use microscopes?A: Cells are small
  4. 4. Before…
  5. 5. Compound Microscope• Combines the power of 2 lenses to enlarge the image and blend light toward your eye
  6. 6. Eye piece lens X objective lens 10x X 4x = 40x Low power 10x X 10x = 100x Medium Power 10x X = 400x High Power 40x
  7. 7. Eyepiece or ocular lens• Lens closest to the eye
  8. 8. Objective Lens• Lens closest to the specimen or object
  9. 9. Nosepiece• Objectives fastened to this revolving structure
  10. 10. Stage• Where you place your slide
  11. 11. Stage clips• Hold slide in place
  12. 12. Body Tube• Light travels through here
  13. 13. Light Source• Provides light
  14. 14. Diaphragm• Regulates the light reaching the objective lens
  15. 15. Base• Supports the microscope
  16. 16. Arm• Holds the body tube, acts as a handle
  17. 17. Coarse focusing knob• Used to focus under low power only
  18. 18. Fine focusing knob• Used to focus under high power only
  19. 19. A microscope reverses and inverts the image of an object seen under itBeforeviewingunder themicroscope eWhileviewing eunder themicroscope
  20. 20. Things moving under a microscope areactually moving in the opposite direction
  21. 21. Things moving under a microscope areactually moving in the opposite direction
  22. 22. Stereoscopic light microscope• Give you 3D view of an object• Used to look at thick things light can’t pass through
  23. 23. Electron Microscopes• Can magnify things more than 300,000 times
  24. 24. Transmission electron microscope • Used to study parts inside a cell
  25. 25. Scanning Electron Microscope• Used to see the surfaces of whole objects
  26. 26. Cell Theory1. All organisms are made up of one or more cells2. Cells are the basic units of structure and function in all organisms3. All cells come from cells that already exist
  27. 27. 2-2 Cell Structure
  28. 28. Living cells are dynamic and have several things in common• Membrane• Cytoplasm (gel-like material)• Nucleus (control center)
  29. 29. There are 2 basic types of cells1. Prokaryotic – no nucleus2. Eukaryotic – has a nucleus
  30. 30. Cell Membrane• Structure that forms the outer boundary of the cell and allows only certain materials to move in and out of the cell
  31. 31. Features of the cell membrane• Flexible• Double layer of fats with some proteins scattered throughout
  32. 32. Cytoplasm• Gel-like material inside the cell membrane
  33. 33. Organelles• Structures within the cytoplasm of eukaryotic cells
  34. 34. Nucleus• Structure that directs all the activities of the cell• Contains the DNA
  35. 35. Chromatin• Made up of protein and DNA (genetic blue print)
  36. 36. Endoplasmic Reticulum• Folded membrane that moves materials around in the cell• Some have ribosomes on them, some don’t
  37. 37. Ribosomes• Make proteins• Some found on ER• Others in cytoplasm
  38. 38. Golgi Bodies• The packaging and secreting organelles of the cell
  39. 39. Mitochondria• Where food molecules are broken down and energy is released
  40. 40. Lysosomes• Digests wastes and worn out cell parts
  41. 41. Vacuoles• Storage areas, store water, food, wastes• Small in animals and large in plants
  42. 42. Cell Wall• Rigid structure outside the cell membrane that supports and protects the plant cell
  43. 43. Chloroplasts• Organelles where light energy is changed into chemical energy in the form of a sugar called glucose (C6H12O6)
  44. 44. Chlorophyll• Chemical in chloroplasts that traps light energy – reflects green light
  45. 45. Bacterial Cells• Prokaryotic• Don’t have membrane – bound organelles
  46. 46. Features of bacterial cells• Cell wall and cytoplasm• Single chromosome• No nuclei• Ribosomes
  47. 47. 2-3 Cell Organization
  48. 48. Nerve Cell • Send impulses through your body
  49. 49. Red Blood Cells • Can change shape • Flexible • Move through the duct work of your blood vessels
  50. 50. Plant Vessel Cell • Transports water and minerals throughout the cell
  51. 51. Tissues• Groups of similar cells that do similar things• Ex.) smooth muscle tissue
  52. 52. Organ• A structure made up of different types of tissues that work together• Ex.) stomach
  53. 53. Organ System• A group of organs working together to do a certain job• Ex.) digestive system

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