AP Lab #13 Enzyme Activity August 28, 2014 Sarah Shafik PURPOSE: Background: Enzymes are proteins that speed up the rate of a chemical formula. They lower a reaction?s activation energy, and are not consumed by the reaction either. Hypothesis: If the enzyme concentration decreases, then the enzyme activity will also decrease. If the substrate concentration decreases, then the enzyme activity will also decrease. If the pH increases, then the enzyme activity will also increase. If the temperature increases, then the enzyme activity will also increase. Key Terms Definitions: Enzymes: a macromolecule serving as a catalyst Catalase: a common?enzyme?found in nearly all living organisms