Properties of Water The extraordinary qualities of water are emergent properties resulting from the hydrogen bonding that orders molecules into a higher level of structural organization--Campbell Cohesion Cohesion: The attraction of like molecules to each other. In waters case, by hydrogen bonding. Function in Life: Allows for the transport of water & nutrients against the flow of gravity in plants Cohesion Surface Tension A measure of how difficult it is to stretch or break the surface of a liquid Water has a high surface tension Function in Life Some organisms can walk, stand or run on water without breaking the surface Moderation of Temperature Specific Heat The amount of heat that must be absorbed or lost for 1 g of a substance to change its temperature by 1 degree C Water has a high specific heat (1 cal/1 g/degree C) Function in Life Water changes temperature slowlycreating stable temperatures in large bodies of water and moderating climate Organisms, too, change temperature more slowly Water is Least Dense as a Solid Ice Floats!! Result of hydrogen bonding & waters crystalline structure Function in Life Ice insulates liquid water ad allows life to live beneath the surface Water is a Versatile Solvent Solvent The dissolving agent in a solution Waters polar properties help it dissolve substances Function for Life Polar molecules and ions dissolve in water of biological fluids: blood, plant sap, and cellular liquid