Section 1. Introduction “Enzymes are proteins which have catalytic functions” [1], “which speed up or slow down reactions” [2], “essential for the maintenance and activity of life” [1]. They are each very specific and will only work when a particular substrate fits their active site. An active site is “a region on the surface of an enzyme where the substrate binds and the reaction occurs”[2]. “Lactase is an enzyme that breaks down lactose, the sugar found in milk. It is produced by the cells that line the small intestine. Most people are born producing lactose, but often produce less as they age, causing lactose intolerance. Symptoms include nausea, bloating, and diarrhea, to name a few. This enzyme is produced commercially as a dietary supplement to help them digest lactose”[3]. The aim of this experiment is to study the specificity of the enzyme and whether its function is under the influence of environmental factors such as pH and temperature. To test specificity, we used lactase in several test tubes in the presence of lactose and sucrose to determine which would give the highest concentration of glucose, which is one of the products of lactase. The test tubes each contained milk (lactose) or sucrose, as well as lactase enzyme or water, which is used as a negative control. We hypothesized that the enzyme is specific and will break down lactose, but not sucrose. We then discovered that our hypothesis was correct because it proved that the lactase enzyme was specifically hydrolyzed lactose. The test tube containing milk and lactase is the only one that contains glucose; the others containing sucrose and lactase did not contain any. Biology 5: Enzyme Lab Report ...... middle of paper ...... is closest to body temperature (25°C); boiling water (100°C) denatures the enzyme, and that the enzyme cannot function properly if placed in ice (4°C). Both the D.4°C (100 mg/dL) and E.25°C (300 mg/dL) test tubes release glucose results while the F.100°C test tube releases absolutely no concentration of glucose. glucose. Carrying out this experiment helped us understand better. of enzymes. Observing and recording the enzymatic reactions was very useful, nothing compared to learning them in a book or in a PowerPoint, it took time and research to get the facts straight. This experiment helped us understand how specific lactase really is and how different each test tube's reaction is. Completing this lab report helped me understand the importance of lactase, and for future experiments, it taught me how to make valid hypotheses and predictions..