1. Properties Important in Biology

2.  Life and Evolution  Cells:70-95%  Earth: 3/4  Three states  Ecosystems

3.  Hydrogen bonds - intermolecular  Remember charges for each side-unequal distribution  Electronegativity of oxygen attracts the positive hydrogen  Transient

4. Earth is fit for Life

5.  Water sticks to Water ◦ Capillary action  Sand and Soil  Transpiration ◦ Surface tension Water sticks to other surfaces adhesion

6.  Transpiration

7.  Capillary Action

10.  Water to other molecules  Capillary action returns  Applications become important for athletes!

12.  Water resists temp changes  Absorbs heat from air that is warmer  Releases heat to air that is cooler  Heat reservoir!  Oceans have relatively stable temp/Coastal areas stable  Marine environment is stable

13.  Heat passes from warmer to cooler  Ice absorbs liquid heat  Water resists temperature changes

14.  Heat that a liquid absorbs to go liquid to gas  Moderates climates as oceans evaporate and then condenses to form rain  Weather patterns

15.  Hottest molecules leave, the surface liquid left behind is cooler  Contributes to lake and pond temp. and prevents terrestrial life from overheating

17.  Expansion upon freezing  Ponds and lakes- thermal mixing  Temp drop 4 0 - 0 0 /expansion- molecules stop moving  Floating ice insulates life below as it releases heat

18.  Water gathers around polar molecules  Each molecule in cloud of water ◦ Sugar ◦ Salt

19.  Sodium +  Chloride -  Alternating ions are held together by electrical charges

23.  Water forms hydrogen bonds with cellulose of cotton  Towels dry you off- water pulled into the towel

24.  Solvent  Solute  Hydrophilic (ionic and polar molecules/hydrophobic (nonpolar molecules)

25.  Biological Rx’s involve solutes dissolved in water  Plasma- 90% water  Cells- 75-95% water

26.  Biological solutions maintain pH because of buffers  Acids: increase H +  Bases: reduces H +  Buffers

27.  Light Penetrates ◦ Tissues ◦ Aquatic environments

28.  Fossil fuel burning creates sulfer oxides and nitrous oxides+ water=strong acids in rain  Coal production more oxides+wind= carry acids for miles as rain  Fossil fuel burning creates carbon dioxide ◦ Reflective blanket preventing heat escape ◦ Absorbed by oceans