1. BIOCHEMISTRY

2. Water
Polarity—due to uneven distribution of electrons between the oxygen and hydrogen atoms, one end of the water molecule is slightly negative and one is slightly positive
The polarity of water allows hydrogen bonds to form between its molecules and is responsible for many of its special properties

3. Special Properties of Water
Cohesion--attraction between molecules of the same substance; because of the hydrogen bonds, water is extremely cohesive
Adhesion--attraction between molecules of different substances

4. Acids and Bases Water can react to form ions
Water forms hydrogen ions (H+) and hydroxide ions (OH-)
An acidic solution is a compound that contains high concentrations of H+ ions
A basic solution, or alkaline, is a compound that contains low concentrations of H+ (high concentrations of OH-)

5. pH Scale pH is a measure of the concentration of H+ ions in a solution
The scale goes from 0 to 14
7 is neutral meaning the solution is not an acid nor a base
Acids have a pH below 7
Bases have a pH above 7