The purpose of this lab is to test for enzyme activity, look at enzyme specificity, and how temperature affects enzyme activity.
I believe that the room temperature activity will produce the most activity.
3% hydrogen peroxide, a household blender, potatoes (3 medium size potatoes, that are peeled and quartered), tap water, 8 test tubes, 8 transfer pipets, sugar packets, salt, a small saucepan, a refrigerator with a freezer, stove, 4 clear plastic cups, tongs (to remove test tubes from boiling water), 4 coffee cups, cheesecloth to filter the potato extract, a wax pencil or Sharpie marker, a ruler, scale or balance, 250 ml graduated cylinder, and oven mitt or tongs. Methods:1. Research (online) the reaction between catalase and hydrogen peroxide and be familiar with the reactants, products, and enzyme. You will include the overall reaction in your lab report for this experiment. We will measure enzyme activity by measuring the height of the bubbles produced.
2. Prepare the potato extract (catalase) using the following technique: – peel 3 medium size potatoes and cut them into quarters
-add the potatoes to the blender with 250 mls of tap water to cover the potatoes and blend on high until the potatoes are pureed (blended to a thick liquid or paste) – place a cheesecloth over a container and use the cheesecloth to obtain the liquid portion (only) of your potato puree. You can squeeze the cheesecloth in the end to obtain the final portions of the liquid from the puree. – Make a 1% sucrose solution using the method describe in your osmosis lab. – Make a 1% salt solution by measuring 1 gram of salt using your scale or balance, add this to your graduated cylinder and then fill to the 100 ml mark. You can then transfer this mixture to a small saucepan, heat and stir until the mixture is dissolved.
Experiment 1: Testing for Enzymatic Activity
Add 3mls of the following solutions to a labeled test tube using a fresh transfer pipet with each new solution:
– test tube 1: tap water
– test tube 2: 1% sucrose solution
– test tube 3: 1% salt solution
– test tube 4: 3% hydrogen peroxide
Add 2 mls of the catalase solution (liquid portion of the potato extract) to each test tube and place into a plastic cup to keep it upright. Pick up each test tube, tap the bottom/ swirl the contents and then using your ruler record in Table 1 the bubble height (if any) that is produced. Remember to include this table (with a strong title) in your lab report.
Experiment 2- Testing the Effect of Temperature on Enzyme Activity Step 1: Label the test tubes 1, 2, 3 and 4, where test tube 1 represents the sample placed on the counter at room temperature, test tube 2 represents the tube placed in the refrigerator, test tube 3 represents the tube placed in the freezer, and test tube 4 represents the sample exposed to boiling water. You will expose catalase to each of these four conditions. Step 2: Place a saucepan with tap water on a burner and bring to a boil.
Use the thermometer to identify and record the temperature for room temperature, in your refrigerator, in your freezer, and then research the temperature of boiling water (do not take this temperature) and record them in Table 2.
Place the test tubes into separate coffee cups to maintain the upward position. Add 2 mls of the catalase solution to each of the test tubes and then place tubes1, 2, and 3 in the conditions described above. For test tube 4, fill the coffee mug half full of boiling water and then place test tube 4 in this container. Do not place the test tube into the pan of boiling water.
Allow the tubes to sit for 5 minutes, then remove the tubes from the conditions mentioned above (note: be careful to use an oven mitt or tongs to remove the test tube exposed to boiling water from the coffee cup). Step 6: Then add 3 mls of 3% hydrogen peroxide, swirl all tubes, and measure the bubbles produced by measuring bubble height (if any are produced). Record this data in Table 2.
Results: Enzymatic Activity Test
Test Tube #
Height of Bubbles
1% sucrose solution
1% salt solution
3% hydrogen peroxide
Temperature on Enzyme Activity
Test Tube #
Temp. of Condition
Amount of Hydrogen Peroxide
Height of Bubbles
The higher the bubbles, then the more enzyme activity is present. We are specially observing the activity of enzymes being artificially produced. It is important to use fresh transfer pipets for each new solution because if not then the lab will be inconclusive due to contamination. My hypothesis was wrong because I further investigate and found that room temperature does not improve activity as much as boiling water.