Properties Important in Biology
Life and Evolution Cells:70-95% Earth: 3/4 Three states Ecosystems
Hydrogen bonds - intermolecular Remember charges for each side-unequal distribution Electronegativity of oxygen attracts the positive hydrogen Transient
Earth is fit for Life
Water sticks to Water ◦ Capillary action Sand and Soil Transpiration ◦ Surface tension Water sticks to other surfaces adhesion
Transpiration
Capillary Action
Water to other molecules Capillary action returns Applications become important for athletes!
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
Heat passes from warmer to cooler Ice absorbs liquid heat Water resists temperature changes
Heat that a liquid absorbs to go liquid to gas Moderates climates as oceans evaporate and then condenses to form rain Weather patterns
Hottest molecules leave, the surface liquid left behind is cooler Contributes to lake and pond temp. and prevents terrestrial life from overheating
Expansion upon freezing Ponds and lakes- thermal mixing Temp drop /expansion- molecules stop moving Floating ice insulates life below as it releases heat
Water gathers around polar molecules Each molecule in cloud of water ◦ Sugar ◦ Salt
Sodium + Chloride - Alternating ions are held together by electrical charges
Water forms hydrogen bonds with cellulose of cotton Towels dry you off- water pulled into the towel
Solvent Solute Hydrophilic (ionic and polar molecules/hydrophobic (nonpolar molecules)
Biological Rx’s involve solutes dissolved in water Plasma- 90% water Cells % water
Biological solutions maintain pH because of buffers Acids: increase H + Bases: reduces H + Buffers
Light Penetrates ◦ Tissues ◦ Aquatic environments
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