1. pH Scale

2. The pH Scale
The pH Scale measures the concentration of hydrogen ions in solutions.
All solutions: pH value between 0&14.
Pure H2O = pH 7
Acidic Solutions = pH <7
Basic/Alkaline Solutions = ph >7

3. Acids and Bases
Some compounds release ions when they dissolve in water or react with water molecules.
Compounds that form hydrogen ions (H+) when dissolves in H2O = Acids
Compounds that form hydroxide ions (OH-) when dissolved in H2O = Bases or Alkaline

4. pH Matters
Most cells function best within a narrow range of temperatures and pH (Homeostasis).
Organisms can tolerate only small changes in pH.
Multicellular organisms: The fluid within the cell and the fluids surrounding the cells have a nearly constant pH. This pH is maintained in a number of ways.