Chapter 7 Cell Structure and Function

1. Chapter 7Cell Structure and Function Lab Biology CP

2. Chapter 7:cell structure & function • 7.1 Life is Cellular • 7.2 Cell Structure • 7.3 Cell Transport • 7.4 Homeostasis and Cells

3. 7.1life is cellular

4. 1.) All organisms are made up of one or more cells. 2.) The cell is the basic unit of life. 3.) All cells come from pre-existing cells. The Cell Theoryby Rudolf Virchow, Theodor Schwann, and Matthias Schleiden

5. Robert Hooke: 1st to view cells under the microscope (1665) viewed cork cells (plant cells) Matthias Schleiden Used a microscope to study that all plants are made of cells (1830’s) Other Contributors

6. Microscope History • Anton von Leeuwenhoek • Made the 1st simple microscope • Looked at pond water • Magnified 270x

7. A subject was placed on the needle and could be positioned with the adjusting screw. Leeuwenhoek Microscope

8. Types of Microscopes • Leeuwenhoek microscope (270x) • Fluorescence microscope (1500x) • Phase contrast microscope (1500x) • Brightfield/Darkfield microscope (2000x) • Transmission electron microscope (100,000x) • Scanning electron microscope (200,000x)

9. Electron Microscopes • Scanning Electron Microscope • A beam of electrons is scanned over the surface of the specimen • Produces 3-D images • Transmission Election Microscope • Make it possible to explore cell structures and large protein molecules • Electrons can only pass through thin samples, so cells and tissues must be cut thin

11. Microscope Parts • Ocular Lens/Eyepiece – what you look through • Body tube – supports the ocular lens/eyepiece • Nose piece – where the objectives are located • Arm and Base- what you carry the microscope by • Stage- where the slide is placed • Adjustments: • Course adjustment- lowers the stage up and down • Fine adjustment - focusing • Light- provides a light source to view your slide • Diaphragm- controls how much light is let in • Stage Clips – holds the slide in place

12. View through a microscope • Upsidedown and inverted http://www.youtube.com/watch?v=X-w98KA8UqU

13. Cells

14. Some different types of cells

15. Common Cell Traits(All cells have these) • 1.) Cell Membrane: • Outer covering • Plant Cells have a Cell Wall also • 2.) Cytoplasm: • Gel-like material inside of the cell

16. Cell Types • Eukaryotes (Eukaryotic): • Have membrane-bound structures in their cells and a nucleus • Nucleus: brain of the cell; genetic info here • Organelles: membrane-bound structures • Animal and Plant Cells • Prokaryotes (Prokaryotic): • Do not have membrane-bound structures in their cells • Bacteria and pond scum

17. Eukaryotes(have membrane-bound organelles)

18. Prokaryotes(Do NOT have membrane-bound organelles)

19. 7.2cell structure

20. Outer Coverings of Cells • Cell Membrane • Found in ALL cells • Made of a protein, lipid bi-layer • Semi-permeable • Fluid-Mosaic Model • Cell Wall • Found in plants only • Tough outer covering • Made up of cellulose • Also made up of pectin and lignin

21. Cell MembraneStructure

22. Cell WallStructure

23. Cell Membrane and Cell Wall Comparison

24. Organelles(membrane bound organelles in inside of the cell) • Nucleus • Mitochondria • Endoplasmic Reticulum • Smooth and Rough • Ribosomes • Golgi Bodies • Lysosomes • Cytoskeleton • Chloroplasts (plant cells only)

25. Center of cell Brain of the cell Directs all the cell’s activities DNA located here Nucleus

26. Deoxyribonucleic Acid A Nucleic Acid Organized into chromosomes DNA segments that carry genetic information are called genes DNA

27. Chromosomes • long pieces of DNA found in the center (nucleus) of cells • come in pairs • Normally, each cell in the human body has 23 pairs of chromosomes (46 total). • half come from the mother • the other half come from the father

29. Powerhouse of the cell Provides energy for the cell Where Cellular Respiration takes place Mitochondria

30. Transports materials around the cell 2 Types: Rough ER: contains ribosomes Smooth ER: does NOT contain ribosomes Endoplasmic Reticulum (ER)

31. Ribosomes • Make proteins • Located in 2 places • On Endoplasmic Reticulum • Free-floating in the cytoplasm

32. Stacked flattened membranes Sort and package proteins and other substances into vesicles Deliver substances to other parts of the cell “Post Office” Golgi Bodies(a.k.a. Golgi Apparatus)

33. Digests wastes inside of the cell Like a “garbage disposal” Lysosomes

34. Cytoskeleton • Maintains cell shape • Moves cell parts • Helps cell move • Made up of microfilaments and microtubules

35. Microfilaments & Microtubules • Microfilaments: threadlike structures made up of protein called actin • responsible for movement • Microtubules: • Hollow structures made up of protein called tubulins • Maintain cell shape • Important in cell division • Formed from Centrioles

36. Microfilaments & Microtubules

37. Vacuoles • In Plant Cells • 1 Large Central Vacuole • Largest portion of the cell • Store water, salts and proteins • In Animal Cells • Vacuoles: Controls water content • Vesicles: move materials between cell organelles

38. What Plants Cells HAVE that Animal Cells Don’t • 1.) Cell Wall • 2.) Chloroplasts • Make chlorophyll (green pigment) • Involved in photosynthesis • 3.) Central Vacuole http://www.youtube.com/watch?v=Fzj6TRnXmps&feature=related

39. Animal Cell (eukaryotic)

40. Plant Cell (eukaryotic)

41. What do cells make? • Cells  Tissues  Organs  • Organ systems  Organisms

42. 7.3cell transport

43. Passive Transport • How the cell regulates the movement of molecules from one side of the cell membrane to the other WITHOUT ENERGY • 3 Types: • 1.) Diffusion • 2.) Facilitated Diffusion • 3.) Osmosis http://www.youtube.com/watch?v=AYNwynwaALo

44. Diffusion • When particles move from an area of high concentration to low concentration • Depends on random particle movement

45. Facilitated Diffusion • Process in which large molecules that can’t directly diffuse across a cell membrane, cross at certain protein channels instead • Some cells have certain proteins that act as channels or carriers and allow for quicker, easier movement of large molecules across a cell membrane

46. Osmosis • An example of facilitated diffusion • How water passes a selectively permeable cell membrane • Aquaporins: water channel proteins that allow the passing of water across the membrane http://www.youtube.com/watch?v=sdiJtDRJQEc

47. How Osmosis Works • Isotonic • When the solution concentration is the same both inside and outside of the cell • Hypertonic • When comparing 2 solutions, the solution with the greater concentration of solutes • Hypotonic • When comparing 2 solutions, the solution with the lesser concentration of solutes

48. Osmotic Pressure • Pressure that must be applied to prevent osmotic movement across a selectively permeable membrane • Can cause an animal cell in a hypertonic solution to shrink • Cells can also burst

49. The Effects of Osmosis on Cells

50. Active Transport • The movement of materials against a concentration difference • Requires ENERGY • Types: • Molecular Transport (small molecules) • Bulk Transport (large molecules) http://www.youtube.com/watch?v=1ZFqOvxXg9M&feature=related