3. About 2/3 of the mass of a cell is made up of water, and most of the biochemical processes of life occur in water solutions.

4. Therefore, the water inside and outside of cells is able to carry nutrients into and around cells and wastes away from cells.

5. Pg. 46

6. Properties of Water (pt. 1) Pg. 47

7. Properties of Water (pt. 1) PropertyDescription

8. - the substance that does the dissolving. (liquid) - the substance that is dissolved. (solid) A large number of substances will dissolve in water. Solute Solvent

9. PropertyDescription Universal Solvent A large number of substances will dissolve in water

10. Universal Solvent Water (solvent) Salt (solute) solution

11. One side of a water molecule is slightly negative (-) and the other side is slightly positive (+).

12. PropertyDescription Polar Molecule Hydrogens are slightly positive and oxygen is slightly negative

13. Polar Molecule

14. Like a magnet, the positive end of one water molecule forms a bond between the negative end of another water molecule

16. PropertyDescription Hydrogen Bonds Bond formed from the negative end of one water molecule and the positive end of another

17. Hydrogen Bonds

18. Water molecules stick to each other (example: This is the reason why water is found in drops; perfect spheres.

19. Water molecules stick to other surfaces (water sticking to a spider web)

20. PropertyDescription Cohesion Adhesion Water sticking to itself Water sticking to other surfaces

21. Cohesion (water to water) Adhesion (water to car surface)

22. Pg. 48

23. Properties of Water (pt. 2) Pg. 49

24. Properties of Water (pt. 2) PropertyDescription

25. Water has the ability to “climb” structures (as in water climbing a glass tube or inside a tree)

26. PropertyDescription Capillary Action Water has the ability to climb structures

27. Capillary Action

28. water has the ability to support small objects. The hydrogen bonds between neighboring molecules cause a “film” to develop at the surface Organisms like the water strider can be seen taking advantage of this property.

29. PropertyDescription Surface Tension The hydrogen bonds between water molecules cause a “film” to develop at the surface

30. Surface Tension

31. Water is able to absorb a large amount of heat energy before it changes temperature.

32. - As a result, lakes and oceans stabilize air and land temperatures. Large bodies of water can affect the climate.

33. PropertyDescription Resistance to Temperature Change Water can absorb large amounts of heat energy before changing temperature

34. Resistance to Temperature Change

35. For most substances, solids are more dense than liquids. But the special properties of water make it less dense as a solid - ice floats on water!

36. When water freezes, the water molecules line up, and as they do, they move farther apart !

37. PropertyDescription Solid Expansion Ice floats (less dense as a solid) Provides an insulation layer for lakes and ponds

38. Solid Expansion

39. PropertyDescription Reactant / Product Water is used or is a by-product of reactions

40. Reactant / Product

46. Water Acid gets stronger as number decreases Base gets stronger as number increases pH Scale Pg. 72 > H+ < OH+

47. pH Notes Pg. 73

48. pH Notes 1.pH - a measurement of how basic or acidic a substance is 2. pH scale – ranges from 0 to 14

50. 3.AcidsBases pH < 7 Sour taste Lots of Hydrogen Ions (H + ) pH > 7 Bitter Taste Lots of Hydroxide Ions (OH - )

51. Inorganic Substances HOH So what is water?? A little bit Acidic A little bit Basic = Neutral

52. 4.Buffers Compound that prevents changes in pH with the addition of acid or base Controls pH (homeostasis) Organisms have natural buffers in their bodies

53. pH Card Activity Use the pink, green, and blue index cards to make a pH scale from 0-14 Place your 5 white index cards in the proper locations above your scale, indicating which part of the scale is acid, which part is basic and which part is neutral. NOTE: Acids release Hydrogen ions and bases release hydroxide ions.

54. Clues 1.As acids get stronger, the pH gets lower 2.As bases get stronger, the pH gets higher 3.The concentration of Hydrogen ions is 1 at a pH of 7. 4.The lowest pH has the highest concentration of H+ ions and the highest pH has the least

55. Clues 5.We drink acids, not bases. 6.Water is neutral. 7.The strongest acid is found in your cars. 8.The strongest base unclogs your sink. 9.We swim in this very weak base 10.Our body eliminates this very weak acid.

56. Clues 11.Your bath tub may have a pH of 12. 12.You favorite drink has 10,000 times more H+ ions than water. 13.Bleach is stronger than ammonia. 14.Lemons beat tomatoes.

57. pH 0 = Battery Acid7 = Water 1 = HCl8 = Ocean Water 2 = Lemon Juice9 = Baking Soda 3 = Soda10 = Milk of Magnesia 4 = Tomato Juice 11 = Ammonia 5 = Coffee 12 = Soapy Water 6 = Urine 13 = Bleach 14 = Liquid Drainer

58. It decreases (becomes more acidic) It increases (becomes more basic)

59. Hydroxide ions because of the OH Substance that prevents changes in pH To maintain pH levels in our bodies (homeostasis)

60. To determine if living organisms have natural buffers in their bodies to prevent drastic changes in pH

61. I – Increase D – Decrease S – Stay the Same

66. Conclusion: A scientific conclusion is an objective discussion of the results. By the end of the year, you will be expected to write your own conclusions. For the first few labs, please complete these sentence prompts to write your conclusion. The purpose of this lab was to… The hypothesis stated that……. This hypothesis was proved correct/ incorrect because the total change in pH became _______ in water with the addition of HCl and ______ with the addition of NaOH. The pH became _______ in the liver homengenate with the HCl and _______ with the NaOH. The pH became _________ in the buffer solution with HCl and _______ with the addition of NaOH. The liver homogenate acted more like the …. In this lab it was determined that in order for your body to maintain homeostasis and resist changes in pH… (what must be present?) * Errors that may have occurred in this lab were…