2. Cell Structure and Transport

3. 7-1 Objectives Describe the tenets of the cell theory Compare the characteristics of prokaryotic and eukaryotic cells Describe the parts of a light and electron microscope

4. The Cell Theory  All organisms are composed of one or more cells. 7.1 Cell Discovery and Theory Cellular Structure and Function  The cell is the basic unit of structure and organization of organisms. Chapter 7  All cells come from preexisting cells.

5. Basic Cell Types -All cells have a plasma membrane Prokaryotic Cell  Simple structure Cellular Structure and Function  Contains a plasma membrane  Does not contain membrane-bound organelles  No nucleus 11,000x 7.1 Cell Discovery and Theory Chapter 7

9. Eukaryotic Cell  More complex structure Cellular Structure and Function  Contains a plasma membrane  Membrane cell organelles 7.1 Cell Discovery and Theory Chapter 7

16. 7.2 The Plasma Membrane Objectives 1.Describe how a cell’s plasma membrane functions 2.Identify the roles of proteins, carbohydrates, and cholesterol in the plasma membrane

17. Plasma Membrane  Thin, flexible boundary between the cell and its environment 7.2 The Plasma Membrane Cellular Structure and Function Chapter 7

18. Selective Permeability Cellular Structure and Function  The plasma membrane controls the movement of substances into and out of the cell. 7.2 The Plasma Membrane Chapter 7

19.  The plasma membrane is composed of the phospholipid bilayer. Cellular Structure and Function 7.2 The Plasma Membrane Chapter 7

20. Fluid Mosaic Model Cellular Structure and Function  “float” in the membrane. Other Components  Proteins  Cholesterol  Carbohydrates 7.2 The Plasma Membrane Chapter 7

21. Proteins Cellular Structure and Function  Transmit signals inside the cell  support structure  Provide pathways for substances to enter and leave 7.2 The Plasma Membrane Chapter 7

22. Cholesterol Cellular Structure and Function  Prevents fatty acid tails from sticking together 7.2 The Plasma Membrane Chapter 7

23. Carbohydrates Cellular Structure and Function  Identify chemical signals 7.2 The Plasma Membrane Chapter 7

24. Plasma membrane

25. 7.3 Structures and Organelles Objectives 1. Identify the structure and function of the parts of a typical eukaryotic cell. 2. Compare and contrast structures of plant and animal cells.

26. Cellular Structure and Function Animal Cell Plant Cell Plant and Animal Cell Structures 7.3 Structures and Organelles Chapter 7

27. Cellular Structure and Function 7.3 Structures and Organelles Chapter 7

28. Cellular Structure and Function 7.3 Structures and Organelles Chapter 7

29. Cellular Structure and Function 7.3 Structures and Organelles Chapter 7

30. Cellular Structure and Function 7.3 Structures and Organelles Chapter 7

31. Cilia  Short, numerous projections that look like hairs Cellular Structure and Function Flagella  Longer and less numerous than cilia  Create movement with a whiplike motion 400x 26,367x 7.3 Structures and Organelles Chapter 7

32. Summary of cell parts http://glencoe.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/free/0 078695104/383931/Table7_1a.swf::Summary%20of%20Cell%20Str uctures%20-%20A http://glencoe.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/free/0 078695104/383931/Table7_1a.swf::Summary%20of%20Cell%20Str uctures%20-%20A http://glencoe.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/free/0 078695104/383931/Table7_1b.swf::Summary%20of%20Cell%20Str uctures%20-%20B http://glencoe.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/free/0 078695104/383931/Table7_1b.swf::Summary%20of%20Cell%20Str uctures%20-%20B http://glencoe.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/free/0 078695104/383931/Table7_1c.swf::Summary%20of%20Cell%20Str uctures%20-%20C http://glencoe.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::550::400::/sites/dl/free/0 078695104/383931/Table7_1c.swf::Summary%20of%20Cell%20Str uctures%20-%20C

33. 7.4 Cellular Transport Objectives 1.Explain the processes of diffusion, facilitated diffusion, and active transport 2.Predict the effect of a hypotonic, hypertonic, or isotonic solution on a cell 3.Discuss how large particles enter and exit cells

34. 2006-2007 Cell Membranes & Movement Across Them

35. Cell (plasma) membrane Cells need an inside & an outside… – separate cell from its environment – cell membrane is the boundary IN food - sugars - proteins - fats salts O2O2 H2OH2O OUT waste - ammonia - salts - CO 2 - H 2 O products - proteins cell needs materials in & products or waste out

36. Building a membrane How do you build a barrier that keeps the watery contents of the cell separate from the watery environment? What substance do you know that doesn’t mix with water?  FATS   LIPIDS  Remember: oil & water don’t mix!!

37. Lipids of cell membrane Membrane is made of special kind of lipid – phospholipids – “split personality” Membrane is a double layer – phospholipid bilayer inside cell outside cell lipid “repelled by water” “attracted to water” phosphate

38. Semi-permeable membrane Cell membrane controls what gets in or out Need to allow some materials — but not all — to pass through the membrane – semi-permeable only some material can get in or out aa H2OH2O sugar lipidssalt waste So what needs to get across the membrane? O2O2

39. Crossing the cell membrane What molecules can get through the cell membrane directly? – fats and oils can pass directly through inside cell outside cell lipid salt aa H2OH2O sugar waste but… what about other stuff?

40. Cell membrane channels Need to make “doors” through membrane – protein channels allow substances in & out specific channels allow specific material in & out H 2 O channel, salt channel, sugar channel, etc. inside cell outside cell sugaraa H2OH2O salt waste

41. How do you build a semi-permeable cell membrane? Channels are made of proteins – proteins both “like” water & “like” lipids bi-lipid membrane protein channels in bi-lipid membrane

42. Protein channels Proteins act as doors in the membrane – channels to move specific molecules through cell membrane HIGH LOW

43. Movement through the channel Why do molecules move through membrane if you give them a channel? ? ? HIGH LOW

44. Molecules move from high to low Diffusion – move from HIGH to LOW concentration

45. Diffusion Move from HIGH to LOW concentration – passive transport – no energy needed diffusionosmosis diffusion of water

46. Simple Diffusion Move from HIGH to LOW inside cell outside cell Which way will fat move? fat LOW HIGH

47. Facilitated Diffusion Move from HIGH to LOW through a channel inside cell outside cell sugar Which way will sugar move? sugar LOW HIGH

48. Diffusion Move from HIGH to LOW concentration – directly through membrane simple diffusion no energy needed – help through a protein channel facilitated diffusion (with help) no energy needed HIGH LOW

49. Simple vs. facilitated diffusion inside cell outside cell lipid inside cell outside cell H2OH2O simple diffusionfacilitated diffusion H2OH2O protein channel

50. Active transport Cells may need molecules to move against concentration “hill” – need to pump “uphill” from LOW to HIGH using energy – protein pump – requires energy ATP

51. Transport summary simple diffusion facilitated diffusion active transport ATP

52. 2006-2007 Osmosis Movement of Water Across Cell Membrane

53. Osmosis Water is very important, so we talk about water separately Osmosis – diffusion of water from HIGH concentration of water to LOW concentration of water across a semi-permeable membrane

54. Keeping water balance Cell survival depends on balancing water uptake & water loss freshwaterbalancedsaltwater

55. Keeping right amount of water in cell Freshwater – a cell in fresh water – high concentration of water around cell cell gains water example: Paramecium problem: cells gain water, swell & can burst – water continually enters Paramecium cell solution: contractile vacuole – pumps water out of cell freshwater No problem, here KABOOM! 1

56. Controlling water Contractile vacuole in Paramecium

57. Keeping right amount of water in cell Saltwater – a cell in salt water – low concentration of water around cell cell loses water – example: shellfish – problem: cell loses water in plants: plasmolysis in animals: shrinking cell – solution: take up water saltwater I will survive! I’m shrinking, I’m shrinking! 2

58. Keeping right amount of water in cell Balanced conditions – no difference in concentration of water between cell & environment cell in equilibrium example: blood problem: none – water flows across membrane equally, in both directions – volume of cell doesn’t change balanced I could be better… That’s better! 3

59. Ice Fishing in Barrow