The Properties of Water “the liquid of life” Water water everywhere and not a drop to drink Don’t go chasing waterfalls Like a bridge over troubled water Rain drops keep falling on my head The fog creeps in on little cats feet It’s Raining men!!! I can see clearly now, the rain is gone Water off a ducks back Let the rain fall down and wake my dreams If all the rain drops were lemon drops and gum drops, oh what a rain that would be Cry me a river Singing in the rain You’re as cold as ice Ice, Ice, baby Smoke on the water Raining on Sunday Walking on water Its like rain on your wedding day I’m H 2 0 intolerant Water is the essence of wetness and wetness is the essence of beauty Its raining its pouring the old man is snoring Now that’s some high quality H2O Rain drops on roses..whiskers on kittens When Chuck Norris goes swimming, he doesn’t get wet…the water gets Chuck

Property of Water Definition and Mechanics Biological Implications Cohesion Water molecules stick together due to H bondsH bonds Transpiration in plants Adhesion Water molecules stick to other polar molecules due to H bonds Transpiration in plants Capillary movement High Specific Heat Water does not change temperature quickly due to hydrogen bonds preventing changes in molecular movement “cooler by the lake” Blood used as heat transport High Heat of Vaporization Water absorbs high quantity of heat before it turns to a gas due to hydrogen bonds Evaporative cooling (Sweating) Temperature stability in water Less Density as a Solid Ice floats because the hydrogen bonds maximize the distance between moleculesmolecules Keeps Aquatic organisms alive during the winter High Surface Tension Hydrogen bonds keep water molecules connected when exposed to air Insects walk on water Water stays together as “drops” Solvent of Life The polar nature of water can dissolve any polar molecule or isolate polar part on large molecules molecules A) Hydrophilic : Water loving (polar) B) Hydrophobic: Water hating (non-polar) Living things are 75% water. Most biologically active molecules are hydrophilic YouTube - Jesus lizard outube.com/w atch?v=k310d _egbFk

Real or Fake? Lack of injury to participants brought to you by Hydrogen Bonds and the Emergent Properties of Water

1. What is pH? The measurement of the Hydrogen (or hydronium) ions found in a hydrophilic solution 2. Where do the H+ come from? A small % of water molecules dissociate into Hydronium (H 3 O+) and Hydroxide (OH-) ions HOH H+ + OH- Water and pH

3. How is pH measured? Increasing H+ (increasing Acid) Increasing OH- (increasing Basic) pH = -log H+ Pure water H+ = or =1x log of = 71x10 -7 Therefore: The pH of pure water is 7 The numbers on the pH scale are in 10X increments

4. What does pH have to do with Biology? A) The pH of the environment can influence biologically active molecules 1) influence chemical reactions 2) affect the interactions of hydrogen bonds 3) determine the structure of proteins

5. How do living organism control pH? a) Living organism use “buffers” to regulate pH b) Buffers work by donating or accepting H+ from the environment 1) organic “weak” acids 2) some proteins (albumin) H 2 CO 3 Increasing OH- HCO 3 + H+ Increasing H+ Examples of buffers

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Water Dissolving Ionic Molecules Water Dissolving Large Molecules With Many Polar Functional Groups Slide 2