Warm Up Objective: Scientists will describe enzymes and what may affect the rate of reactions by conducting and analyzing a lab. What is the topic? What will you be doing? Why is this important? How will you know if you have done well?

Warm Up Objective: Scientists will describe enzymes and what may affect the rate of reactions by conducting and analyzing a lab. What is the topic? Enzymes, what may affect rate of reactions What will you be doing? Conducting and analyzing a lab Why is this important? Understand ourselves—we could not live without enzymes! How will you know if you have done well? Able to describe enzymes and what can affect reaction rates

Introduction Read and annotate. What is important info Introduction Read and annotate. What is important info? What are you doing? What would happen to your cells if they made a poisonous chemical? You might think that they would die. In fact, your cells are always making poisonous chemicals. They do not die because your cells use enzymes to break down these poisonous chemicals into harmless substances. Enzymes are proteins that speed up the rate of reactions that would otherwise happen more slowly. The enzyme is not altered by the reaction. You have hundreds of different enzymes in each of your cells.

Introduction Read and annotate. What is important info Introduction Read and annotate. What is important info? What are you doing? What would happen to your cells if they made a poisonous chemical? You might think that they would die. In fact, your cells are always making poisonous chemicals. They do not die because your cells use enzymes to break down these poisonous chemicals into harmless substances. Enzymes are proteins that speed up the rate of reactions that would otherwise happen more slowly. The enzyme is not altered by the reaction. You have hundreds of different enzymes in each of your cells.

Introduction—Read and annotate. What is important info Introduction—Read and annotate. What is important info? What will you be doing? Each of these enzymes is responsible for one particular reaction that occurs in the cell. In this lab, you will study an enzyme that is found in the cells of many living tissues. The name of the enzyme is catalase; it speeds up a reaction which breaks down hydrogen peroxide, a toxic chemical, into 2 harmless substances--water and oxygen. Light can also break down H2O2 which is why the chemical is sold in dark containers.

Introduction—Read and annotate. What is important info Introduction—Read and annotate. What is important info? What will you be doing? Each of these enzymes is responsible for one particular reaction that occurs in the cell. In this lab, you will study an enzyme that is found in the cells of many living tissues. The name of the enzyme is catalase; it speeds up a reaction which breaks down hydrogen peroxide, a toxic chemical, into 2 harmless substances--water and oxygen. Light can also break down H2O2 which is why the chemical is sold in dark containers.

Introduction—Read and Annotate The reaction is: 2H2O2 → 2H2O + O2 This reaction is important to cells because hydrogen peroxide is produced as a byproduct of many normal cellular reactions. If the cells did not break down the hydrogen peroxide, they would be poisoned and die. In this lab, you will study the catalase found in liver cells. You will be using chicken or beef liver. It might seem strange to use dead cells to study the function of enzymes. This is possible because when a cell dies, the enzymes remain intact and active for several weeks, as long as the tissue is kept refrigerated.

Introduction—Read and Annotate The reaction is: 2H2O2 → 2H2O + O2 This reaction is important to cells because hydrogen peroxide is produced as a byproduct of many normal cellular reactions. If the cells did not break down the hydrogen peroxide, they would be poisoned and die. In this lab, you will study the catalase found in liver cells. You will be using chicken or beef liver. It might seem strange to use dead cells to study the function of enzymes. This is possible because when a cell dies, the enzymes remain intact and active for several weeks, as long as the tissue is kept refrigerated.

Roles and Safety Follow the procedure. Wear goggles and gloves. Roles: Facilitator: Read the procedure for your group. Keep your group on task. Recorder: Record your group’s results. Share these results with your group. Reporter: Share your group’s results and CER. Materials Manager: Cleans materials at the end of the lab. Puts them back at the station. Safety Manager: Ensure everyone is wearing goggles and gloves. Report any issues to Ms. Reed.

Part A – Demonstration of Normal Reaction 2. What gas is being released? Has it gotten warmer or colder? Is the reaction endothermic or exothermic? 3. Assuming the reaction is complete, what is the liquid composed of? What do you think will happen if you had more liver to this liquid? Reaction rate? 4. What is the reaction rate?

Part A – Demonstration of Normal Reaction 2. What gas is being released? oxygen Has it gotten warmer or colder? warmer Is the reaction endothermic or exothermic? exothermic 3. Assuming the reaction is complete, what is the liquid composed of? water What do you think will happen if you had more liver to this liquid? Nothing , bubbles (answers vary) Reaction rate? 0 4. What is the reaction rate? 4

Part A – Normal Reaction Rate Demonstration Is catalase reusable? Claim: Evidence: Reasoning:

Part A – Normal Reaction Rate Demonstration Is catalase reusable? Claim: Catalase is reusable. Evidence: Reasoning:

Part A – Normal Reaction Rate Demonstration Is catalase reusable? Claim: Catalase is reusable. Evidence: Still had reaction with the old liver Same reaction rate as before Reasoning:

Part A – Normal Reaction Rate Demonstration Is catalase reusable? Claim: Catalase is reusable. Evidence: Old liver still reacted. Reaction rate did not change. Reasoning: Catalase is reusable. Evidence is that the old liver reacted and the rate did not change. This must have happened because the liver still had catalase.

Part B-D There are two set-ups at each part. Your group will complete at least one of the stations. If there is time remaining, you will be allowed to do more. Once time has been called, your group will share your data with the rest of the class.

Part B Substance Apple Potato Yeast Rate of Reaction (0-5) Do all living tissues contain catalase? Claim: Evidence: Reasoning:

Part C 2. What is the reaction rate for the boiled liver and peroxide? 3. What is the reaction rate for the cold liver/peroxide? What is the reaction rate for the warm liver and peroxide? How does temperature affect the catalase enzyme? Claim: Evidence: Reasoning:

Part D pH of vinegar = pH of sodium bicarbonate = pH of water = pH of NaOH = Rate of reaction for: Strong acid ___ Acid ___ Neutral ___ Base ___ Strong Base ___ How does pH affect the reaction rate of catalase? Propose a way to refine the experiment to find the exact or optimal pH or temperature of catalase. How does pH affect the activity of enzymes? Claim: Evidence: Reasoning:

Part E (last page) Bonus! Design an experiment with lactaid to break down milk.