1. Units GoalsAnalyze the nature of the relationships between structures and functions in living cells. 1.Explain the role of cell organelles for both prokaryotic and eukaryotic cells. Including the cell membrane, in maintaining homeostasis and cell reproduction. 2.Explain the impact of water on life processes. Osmosis and diffusion

3. How do things get into and out of cells? 1

4. Cells need to get molecules into and out of the cell in order to live. They need to get “ food ” molecules in and “ waste ” molecules out. Membrane Video The Cell Membrane (aka: plasma membrane) 49 Clip

5. The hydrophobic interior inhibits the movement of ions. The membrane can control the movement of molecules (maintaining homeostasis). The Cell Membrane Hydrophilic: water loving Hydrophobic: water fearing

6. Diffusion across the membrane Some molecules like H 2 0, C0 2 and O 2 can move (diffuse) directly across the membrane. What determines which way they will go…in or out??? 51 Concentration C0 2 0202 0202 0202

7. Diffusion Movement of molecules from a place of higher concentration to a place of lower concentration Always higher to lower! No energy input required! 52 The universe WANTS equilibrium!!

9. Osmosis: Diffusion of water through a cell membrane H  L…No energy input required! Osmosis is a special case of diffusion 53

10. What about substances that can’t diffuse through the phospholipid bilayer? 54

11. Membrane Structure There are proteins “stuck” in the membrane that help get molecules & messages into and out of the cells. Basic Cell Structure 55

12. Proteins in Membrane - help get molecules & messages into and out of the cells. Basic Cell Structure 56

13. Proteins in Membrane Remember Goal #1 Function of cell membrane in maintaining homeostasis. -The proteins allow things in and out! -We say that the membrane is “selectively permeable” or “semipermeable” 57

14. Facilitated Diffusion Protein -When molecules pass through a protein in the membrane it is called facilitated diffusion. 54 Energy is NOT required to move substances across the membrane. This is simple diffusion… HL special case of diffusion

16. High Concentration Low Concentration Cell Membrane bilayer Glucose molecules Protein channel 55 Facilitated Diffusion You Tube

17. What if a cell needs to take in or get rid of molecule against the concentration gradient (Low to high) ? 56

18. Active Transport Cells can pump large amounts of some molecules. This takes ENERGY- ATP. L  H Going against the concentration gradient. 57

19. Active Transport Energy is required.Energy is required. Need ATP- the universal energy molecule.Need ATP- the universal energy molecule. Low to highLow to high Energy is required.Energy is required. Need ATP- the universal energy molecule.Need ATP- the universal energy molecule. Low to highLow to high 58

20. 57 You Tube

21. Transport through the membrane -Simple diffusion Energy input NOT required High to low -Osmosis Energy input NOT required Water High to low –Facilitated Diffusion Energy input NOT required Movement through a protein High to low –Active Transport Energy input required Movement through a protein Low to high 60 Transport Review Animations

22. No Energy Required Energy Required

23. Other ways to get molecules into and out of a cell Some molecules are too large to get through the membrane. WWWW eeee bbbb ssss iiii tttt eeee 1.E ndocytosis Into the cell 2. Exocytosis Out of the cell 61 You tube Clip

24. Endocytosis Into Endocytosis Into the cell

25. ENDOCYTOSISENDOCYTOSISENDOCYTOSISENDOCYTOSIS 62

26. 63 Inside Cell Outside Cell Requires Energy

27. 64

28. Inside of the cell Outside of the cell Exocytosis 65

29. Solutions When 2 or more substances are mixed together. 66

30. 3 types of Solutions 1.Hypotonic 2.Hypertonic 3.Isotonic 67

31. Hypotonic 68 CELL Beaker of water and sugar The solution with the lower concentration of solutes is h hh hypotonic solute Cell Grows larger.

32. Isotonic 69 CELL Beaker of water and sugar Solutions with equal solute concentrations are isotonic solute Cell Stays the same size.

33. Hypertonic 70 CELL Beaker of water and sugar The solution with the higher concentration of solutes is hypertonic solute Cell shrinks.

34. Hypertonic, hypotonic, isotonic comparative –These are comparative terms. Tap water is hypertonic compared to distilled water but hypotonic when compared to sea water. 71

35. 3 types of Solutions 72

36. What types of solution? Hypertonic Or Hypotonic 73

37. Plasmolysis Cell membrane shrinks away from the cell wall 74 Hypertonic Turgor Pressure animation

38. Plasmolysis 75

39. Review Clip Question: Why could it be deadly if you drank sea water?

40. Review Transport