AP LAB – ENZYME CATALYSIS LAB WRITE-UP Due Friday, 10/3 or Thursday, 10/2 by 3:30 for 5! Title I. Enzyme Catalysis AP Lab Introduction Brief overview of the lab in general, including the importance, properties of enzymes Specifically, identify the enzyme, substrate, and product involved in the reaction studied Include a brief explanation of the titration procedure and purpose of the KMnO4 Explain the purpose for Parts A, B, C Description of factor changed in Part C Please Note: We will be formulating hypotheses for each factor as a class. You do NOT need to record a written hypothesis. Materials & Methods Do not list materials Provide a one-sentence summary of the procedure used in Part A. Provide a brief description of the procedure used in Part B. Explain the procedure used in Part C by your lab table Then write, “For a complete listing of materials and methods, see lab protocol titled AP Lab 2 – Enzyme Catalysis“ II. III. Data Data Tables for Parts A, B, C Data Table Showing Class Averages for Part B and Class Data for each factor tested in Part C Use the Data Table below as a guide Class Data Posted Enzyme Catalyzed H2O2 Decomposition – Class Data Amount of H2O2 Decomposed (mL) 10 mL H2O2 + 1 mL catalase (10:1) 2X Substrate (20:1) 2X Enzyme (5:1) Increased Temperature (~ 40° C) Decreased Temperature (~ 10° C) 10 30 Time (seconds) 60 120 240 Graph Data Analysis Use class data to determine the initial rate of the reaction and the rates between each of the time points for Part B. Please reconstruct this table in your lab write-up. Please recall that Rate = slope or (change in y) / (change in x) IV. Enzyme-Catalyzed H2O2 Decomposition 5 lines Class averages for Part B Posted Class data for each factor tested in Part C The graph must be big enough to clearly show all 5 lines Include a key 0 – 10 Time Interval (sec) 10 – 30 30 – 60 60 – 120 Reaction Rate (mL H2O2 decomposed/sec) Use Class Data to calculate the rate of reaction from 0 – 30 seconds for each set-up. Set-Up 10 mL H2O2 + 1 mL catalase (10:1) 2X Substrate (20:1) 2X Enzyme (5:1) Increased Temperature (~ 40° C) Decreased Temperature (~ 10° C) Reaction Rate 0 – 30 seconds (mL H2O2 decomposed/sec) 120 – 240 V. 5. 6. Questions All questions must be answered thoroughly in complete sentences that re-state the question. Refer to your graph, calculations done in the Data Analysis section to answer questions 1-3. In Part B, when is the reaction rate the greatest? When is the rate the slowest? Explain. Contrast the effect of increasing substrate concentration versus enzyme concentration on the reaction. Explain the differences seen. Describe the effect of a moderately increased versus decreased temperature on the reaction rate. Provide an explanation. If the temperature was increased even further, construct a hypothesis that predicts the effect on reaction rate. Justify your hypothesis by providing your rationale. Explain why the addition of sulfuric acid stops the reaction. Describe the principle of “induced fit”. Why is this important? Conclusion Was the purpose of the lab accomplished? Elaborate. Identify three controlled variables (constants) and explain the importance of each. In determining the effect of a factor on the rate of enzyme catalysis, what is the experimental control? Explain. Discuss your results for Part C. Do your results support the class hypothesis? Why or why not? Identify possible sources of error. 1. 2. 3. 4. VI. Academic Pledge I pledge, on my honor, that I did not give or receive any unauthorized assistance on this assignment… Then sign your name!