3 Important Functions of Water To dissolve life’s moleculesTransport molecules and ions through living cells and tissues.Moves substances by diffusion- cellular transportTo hold large molecules together by forming hydrogen bonds. For example-carbohydrates and proteins.To maintain optimum temperature (homeostasis)Acts as an insulatorExpands when freezes-erosion and insulation
4 Properties of WaterWater is a polar molecule- a molecule with an unequal distribution of charges.Oxygen-8 protons pull the electrons to one end and the single proton in the hydrogen atom gains a positive charge.Results- weak hydrogen bonds that are easily formed and broken.
5 Life depends on hydrogen bonds in water. Water is a polar molecule.Polar molecules have slightly charged regions.OH_+Nonpolar molecules do not have charged regions.Hydrogen bonds form between slightly positive hydrogen atoms and slightly negative atoms.
7 “Like dissolves like.”Polar solvents dissolve polar solutes.Nonpolar solvents dissolve nonpolar solutes.Polar substances and nonpolar substances generally remain separate.
8 Hydrogen bonds are responsible for three important properties of water. high specific heatcohesionadhesion
9 Many compounds dissolve in water. A solution is formed when one substance dissolves in another.A solution is a homogeneous mixture.Solvents dissolve other substances.Solutes dissolve in a solvent.solution
10 Some compounds form acids or bases. An acid releases a hydrogen ion when it dissolves in water.high H+ concentrationpH less than 7more acidicstomach acid pH between 1 and 3
11 A base removes hydrogen ions from a solution. low H+ concentrationpH greater than 7bile pH between 8 and 9more basic
12 A neutral solution has a pH of 7. pure water pH 7