Acids and bases are important to many chemical processes: maintaining a stable internal environment in the human body, baking a delicious cake, or determining whether a lake can support aquatic life. Reactions involving acids and bases can be described through the transfer of protons. The reactions of acids and bases, which can be monitored with indicators, can range from corrosive behavior to neutralizations that leave no acids or bases behind. To understand the controlling of pH of solutions, buffers are discussed in the laboratory and in the chemistry of the bloodstream. Part of Chemistry: Challenges and Solutions Series.