1. Acids, Bases, and pH Biology

2. Acids Any compound that forms H+ ions when dissolved in water pH of less than 7 Strong acids tend to have values that range from 1 to 3 Example: Vinegar

3. Bases Any substance that forms OH- (hydroxide) ions when dissolved in water pH greater than 7 Strong bases tend to have values that range from 11 to 14 Example: Bleach

4. pH Scale Runs from 0 to 14 Compares acidity/basicity Each increase in a number on the pH scale = 10X higher pH Example: pH of 4 is 100X lower (more acidic) than pH of 6

6. Why is pH important? Organisms have an internal pH that must remain fairly stable for chemical reactions to occur optimally, thus… Controlling pH is essential for homeostasis Buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH