Section 1. Introduction“Enzymes are proteins that have catalytic functions” [1], “that speed up or slow down reactions”[2], “essential for maintenance and activity of life”[ 1]. Each of them is very specific and only works 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 where the reaction occurs”[2].“Lactase is an enzyme that breaks down lactose, the sugar found in milk. It is produced by the cells lining the small intestine. Most people are born producing it, but often consume less of it as they age, which causes lactose intolerance whose 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 different test tubes in the presence of lactose and sucrose to understand which would result in the highest concentration of glucose, which is one of the products of lactase. Each tube contained milk (lactose) or sucrose and the enzyme lactase or water, which is used as a negative control. We hypothesized that the enzyme is specific and breaks down lactose, but not sucrose. We then found that our hypothesis is accurate because it showed that the lactase enzyme specifically hydrolyzed lactose. The test tube containing milk and lactase is the only one that contained glucose; the others containing sucrose and lactase do not. Biology 5: Enzyme Lab Report ...... middle of paper ...... is closest to body temperature (25°C); boiling water (100°C) denatures the enzyme and the enzyme is unable to function properly if placed in ice (4°C). Both the D. 4°C (100 mg/dL) and E.25°C (300 mg/dL) tubes release glucose results while the F.100°C tube releases absolutely no glucose concentration. Completing this experiment helped us understand enzymes better. Observing and recording enzymatic reactions was very helpful, nothing compared to learning about them in a book or PowerPoint, it took time and research to get accurate facts. This experiment helped us understand how specific lactase really is and how different each test tube's reaction was. Completing this lab report helped me understand how important lactase is and for future experiments taught me how to make valid hypotheses and predictions.