IB biology Cells Topic

1. Cell Membrane Structure and Function

4. The Cell Membrane

5. Cell membranes What is their structure?

6. We don’t know currently There are a number of hypotheses and we will consider the one which is currently accepted........

8. The fluid mosaic model Lipids arranged in bi-layer with proteins embedded or associated with them.

9. Phospholipid Molecule Model glycerol fatty acids (hydrophobic) – hate water phosphate (hydrophilic) – like water Draw This

10. Membrane Lipids form a Bi-layer Outside layer Inside Layer

13. The cell membrance is a complex 3d circular structure The cell membrane is a complex 3 d structure .

15. The fluid mosaic model

17. Composition of the cell membrane Phospholipids Peripheral Proteins DRAW THIS Integral Proteins Trans – membrane proteins Cell Membrane

26. Active and Passive Transport Summary

30. Its about concentration The concentration of the solution, with respect to other solutions is important Isotonic --- when both solutions have the same concentration of dissolved substances Hypertonic --- a solution with a higher concentration of dissolved substances Hypotonic --- a solution with a lower concentration of dissolved substances

31. Animal cells Plant cells

32. Two types of transport Passive and Active

35. Diffusion Diffusion is the passive movement of particles from a high concentration of particles to a lower concentration until they are spread out evenly Smell Particles & Air Particles Solution Smell Particles diffused evenly into the Air Particles

41. Diffusion & Photosynthesis CO 2 O 2

44. Facilitated Diffusion Glucose Transport protein Concentration gradient

46. Glucose Cell membrane Transport protein Glucose binds to the transport protein The transport protein turns over and releases glucose onto the inside of the cell, along the concentration gradient Concentration gradient

48. Carrier molecule Cell membrane Transport protein The carrier molecule binds to the transport protein, which opens the pore allowing it to move through the cell membrane. The pore closes once the carrier is inside the cell. Concentration gradient It is possible to stop the action of transport protein with drugs which will block the pore.

50. Osmosis

51. Osmosis

54. Class Activity: Correctly Label Weak Solution Strong Solution Solute Molecule Water Molecule Partially Permeable Membrane Which way will the water flow???

55. Osmosis

56. Osmosis and Animal Cells haemolysis Hypotonic solution Hypertonic solution

57. Osmosis & Plant Cells Turgid Cell Plasmolysed Cell Hypotonic solution Hypertonic solution

58. Plasmolysis in Elodea Plasmolysis in Elodea: http://www.mrphome.net/mrp/Membrane_Transport.html

61. Salt ion Cell membrane Transport protein Ion binds to the transport protein The transport protein turns over and releases the ion onto the inside of the cell, against the concentration gradient Concentration gradient Energy is used

63. Pseudopodia extend to engulf food A food vacuole is formed Pinocytosis works the same, but with no food, only liquid How Endocytosis works

66. Exocytosis the finer detail

67. Bulk Transport

69. Sodium-Potassium Pump

74. Villi and Glucose Uptake

75. Passive vs. Active Transport