the extraordinary properties of water. water is important for all living things average person ~~...
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The Extraordinary The Extraordinary Properties of Properties of WaterWater
WATER is important for all living thingsAverage person ~~ 60-70%
waterHuman brain ~~ 90%
Cells are about 70-95% water
WaterWater
•A water molecule (H2O), is made up of three atoms: one oxygen and two hydrogen.
O
Polar MoleculesBecause of the location ofelectrons in molecules, some molecules have an_________ pattern of____________________
More ___ on one side; More ___ on the other
EX: water
UNEVEN
+-
ELECTRIC CHARGE
WHAT HOLDS MOLECULES TOGETHER?
Molecules are _____________by the________ between ______________regions of nearby molecules
= _____________________VAN DER WAALS FORCES
HELD TOGETHER
ATTRACTION OPPOSITELY CHARGED
Bonds that form between the_________ charged _____________in one molecule and a __________ charged _________in a nearby molecule are called_____________________
POSITIVELY
HYDROGEN BONDS
HYDROGEN ATOM
NEGATIVELY ATOM
HYDROGEN BONDS
EX: water molecules are held together by Hydrogen bonds
Hydrogen BondsHydrogen Bondsone hydrogen bond is weak , but one hydrogen bond is weak , but
many hydrogen bonds are strongmany hydrogen bonds are strong
http://www.northland.cc.mn.us/biology/biology1111/animations/hydrogenbonds.html
CLICK LINK BELOW FOR AN ANIMATION FOR BONDING
Hydrogen bonds
•weak
•form, break, and reform with great frequency
•Each bond only lasts a few trillionths of a second
However, hydrogen bonding is what gives water it’s essential properties…
Each water molecule can form hydrogen bonds with up to four neighbors
WaterWater
•At sea level, pure water boils at At sea level, pure water boils at 100 °C and freezes at 0 °C.100 °C and freezes at 0 °C.
•The boiling temperature of The boiling temperature of water decreases at higher water decreases at higher elevations (lower atmospheric elevations (lower atmospheric pressure). pressure).
•For this reason, an egg will For this reason, an egg will take longer to boil at higher take longer to boil at higher altitudesaltitudes.
Properties of WaterProperties of Water
•What are they?What are they?
Properties of WaterProperties of Water
•CohesionCohesion
Properties of WaterProperties of Water
•CohesionCohesion
•AdhesionAdhesion
This is a great notes interaction! It will help you remember and not get them confused!
Properties of WaterProperties of Water
•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat
Properties of WaterProperties of Water
•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat•High Heat of High Heat of VaporizationVaporization
Properties of WaterProperties of Water
•CohesionCohesion•AdhesionAdhesion•High Specific HeatHigh Specific Heat•High Heat of High Heat of VaporizationVaporization
•Less Dense as a SolidLess Dense as a Solid
CohesionCohesion Attraction between particles Attraction between particles of of the same substance the same substance
- why water is attracted to why water is attracted to itselfitself Results in:Results in:Surface tensionSurface tension (a measure of (a measure of the strength of water’s surface) the strength of water’s surface)
•surface film on water surface film on water -allows insects to walk on the -allows insects to walk on the
surface of water surface of water
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Water Properties
•Polarity
CohesivenessAdhesivene
ss
Surface Tension
• http://www.visionlearning.com/library/module_viewer.php?mid=57
• http://www.youtube.com/watch?v=Qhsxo7vY8ac
Basilisk lizard: The Jesus Lizard
AdhesionAdhesion•Attraction between two different Attraction between two different substances. substances.
- water will make hydrogen - water will make hydrogen bonds with other surfaces such as bonds with other surfaces such as glass, soil, plant tissues, and cotton. glass, soil, plant tissues, and cotton.
.
Copyright Pearson Prentice Hall
•CapillaryCapillary actionaction-water molecules will “tow” each other -water molecules will “tow” each other along when in a thin glass tube. along when in a thin glass tube.
- i.e. transpiration process which plants and trees - i.e. transpiration process which plants and trees remove water from the soil, and paper towels soak up remove water from the soil, and paper towels soak up water.water.
High Specific HeatHigh Specific Heat
Amount of heat needed to raise Amount of heat needed to raise or lower 1g of a substance 1° C.or lower 1g of a substance 1° C.
•Water Water resistsresists temperature temperature change, both for heating and change, both for heating and cooling.cooling.
•Water can absorb or release Water can absorb or release large amounts of heat energy large amounts of heat energy with little change in actual with little change in actual temperature.temperature.
High Heat of High Heat of VaporizationVaporization
Amount of energy to convert Amount of energy to convert 1g or a substance from a liquid 1g or a substance from a liquid to a gasto a gas
• In order for water to In order for water to evaporate, hydrogen bonds evaporate, hydrogen bonds must be broken. As water must be broken. As water evaporates, it removes a lot of evaporates, it removes a lot of heat with it.heat with it.
Water has a high heat capacity
Heat capacity (specific heat) is the quantity of heat required to change the temperature of a substance by 1 degree
Water can store a lot of heat!It changes temperature very slowly
• “Water vapor forms a kind of global ‘blanket’ which helps to keep the earth warm. Heat radiated from the sun-warmed surface of the earth is
absorbed and held by the vapor.”
Water is Less Dense as Water is Less Dense as a Solida Solid
•Ice is less dense as a solid than as a liquid (ice floats)Liquid water has hydrogen bonds that are constantly being broken and reformed.Frozen water forms a crystal-like lattice whereby molecules are set at fixed distances.
Water is Less Dense as Water is Less Dense as a Solida Solid
•Which is ice and which is Which is ice and which is
water?water?
Water is Less Dense as a Water is Less Dense as a SolidSolid
WaterWater IceIce
HomeostasisHomeostasis• Ability to maintain a steady state Ability to maintain a steady state
despite changing conditionsdespite changing conditions• Water is important to this process Water is important to this process
because:because:a. Makes a a. Makes a good insulatorgood insulatorb. Resists temperature changeb. Resists temperature changec. c. Universal solventUniversal solventd. Coolantd. Coolante. Ice protects against e. Ice protects against temperature extremestemperature extremes
WATER IS THE UNIVERSAL SOLVENT
• http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/thermochem/solutionSalt.html
Cells are about 70-95% water90% of cytoplasm is water92% of blood plasma is water97% of tissue fluid and lymph is water
IMPORTANCE OF WATER FOR ORGANISMS
Takes part in metabolic reactions:
• photosynthesis: water is a raw material in the light stage
• Respiration: aerobic respiration produces water
• Anabolism: produced when macromolecules are made
• Catabolism: water is used to break the bonds in macromolecules
REMEMBER: METABOLISM = ANABOLISM + CATABOLISM
Movement of materials through cell membranes:
• Diffusion• Osmosis• Active transport
Turgor pressure plays an important role in the support of plants
Loss of turgor pressure:
Plant wilts
turgor pressure restored
Plant supported