GROUP+2

NAMES: Melody Ashby, Ali Lauro, Mike Tudisco, Lauren Song, Olivia Oskwarek

= The Effect of Concentration of Catalase on Enzyme Activity on Hydrogen Peroxide =

**II. The Investigation** What are some factors that could change the rate of the enzyme-catalyzed breakdown of hydrogen peroxide? What might influence the effectiveness of catalase at making the reaction occur? Brainstorm with your group and list your ideas below.

Your group will choose one variable to investigate. Identify your control. You will design an experiment to test if and how your variable influences the activity of the enzyme. Be prepared to offer your experimental design to the class for constructive criticism. **Record your hypothesis, materials, and data on your group’s Wiki page.**

**III. Data Analysis and Conclusions** * Make any relevant mathematical calculations of your data on you Wiki. * You must graph your data on Excel. On the x-axis: Time (in seconds). On the y-axis: Your variable, appropriately measured. This will be a connected “X-Y Scatter” graph. * Discuss and explain the meaning of your data with your group members. * Research your variable’s effect on enzyme activity by using your textbook or the Internet. IV. Your Wiki Your Wiki must contain the following components: * A Title * A paragraph explaining what enzymes are, what their role is, and explaining the chemical reaction **2 H2O2** **à** **2H2O + O2** * A graph of your findings. * One paragraph for each of the following in the conclusion: - **//Explaining the effect of your variable on your experimen//** **//t.//** **//- How do your experimental findings compare with accepted scientific knowledge of factors affecting enzyme activity? Explain. 6 pts.//** **//- What improvements would you make your experimental design if you had more time and materials?//** * One picture of your set-up. * The names of everyone in your group.

= The Effect of Concentration of Catalase on Enzyme Activity on Hydrogen Peroxide =

Hypothesis: If the Paper Disc is more soaked with catalase, then it will float to the top of the beaker faster.
Independent Variable: The concentration of the enzyme Catalase Dependent Variable: Speed of the breakdown of H202 Materials =Data Analysis and Conclusion= = =
 * 1) 6 Beakers
 * 2) Stop watch
 * 3) Graduated Cylinder
 * 4) Paper discs
 * 5) H2O
 * 6) Catalase

__**Tables:**__








__**Enzymes:**__ Enzymes are organic catalysts that can be reuse d since they do not change during reactions. A specific enzyme is needed in each chemical reaction. Enzymes consist of one ore more polypeptide chains. They are named for the substrate. If the enzyme forms a temporary association with the substance whose reaction it will affect then the enzyme is able to affect the rate of the reaction. The action of the enzyme takes place once the enzyme-substrate complex is formed. The enzyme and product separate once the reactions is finished. New enzymes must be created when the old ones are eventually destroyed.

__**Paragraph 1: Effect of Concentration of the Enzyme Catalase on the experiment**__ The variable tested was concentration of the enzyme catalase, which catalyzes, or speeds up, the breakdown of hydrogen peroxide. When pure 100% catalase was used to test the speed of the breakdown, the breakdown occurred quickly. As the concentration of catalase was reduced, the breakdown of hydrogen peroxide into water and oxygen was slower. During each test, larger amounts of water replaced equal amounts of catalase, so there was less catalase; because there was less catalase, the breakdown of hydrogen peroxide into water and oxygen was slower. The breakdown, effectively, was slower as amounts of catalase were lessened.

__**Paragraph 2: Tests conducted compared to current accepted Scientific Knowledge:**__ According to current accepted scientific knowledge catalase is a very fast reacting enzyme: an increase in concentration of the enzyme catalase (the substrate) will cause an increase in the speed of the breakdown of hydrogen peroxide. The conducted tests showed similar results: when 100% catalase was used, the breakdown of hydrogen peroxide occurred rapidly. When the concentration of catalase lessened as it was replaced by water, the breakdown was slower. The lager the amount of water that replaced an equal amount of catalase, the slower the breakdown was; these tests are in sync with accepted scientific knowledge of catalase.

__Sources:__ "The Effect Of Catalase Concentration On The Breakdown Of Hydrogen Peroxide." //Tallsimon.com: Tallsimon and His Random Stuff//. June-July 2008. Web. 23 Nov. 2010. .

"The Effect of Hydrogen Peroxide on Catalase with Varied Temperature." __123HelpMe.com__. 23 Nov 2010 .

The experiment ran rather smoothly, and delivered accurate results compared to accepted scientific information. However, the experiment did not take place in a high-tech lab, and could use improvements. Firstly, the amount of seconds it took for the small paper discs to travel to the top of the solution would be more accurately times. During certain tests, timing with the stopwatch did not begin until the paper disc had been in the solution for several seconds. To improve the exact timing, several people would hold stopwatches, in case one did not begin just as the paper disc hit the solution. Also, more than just three tests would be conducted. Instead, ten or twenty tests would be conducted because this would more closely resemble the most accurate results.
 * __Paragraph 3: Improvements to Our Experiment:__**

// In our experiment, we did multiple tests to find out what effect if any, the concentration of the catalyst had on the breakdown of oxygen. We started out by finding how fast a paper strip would rise in water after it was submersed in the catalyst. Then we did the same thing but added more and more water to the catalyst, diluting it. To make our experiment better, we could have made sure that the paper was all submersed for the same amount of time. We also could have performed more tests for each time we diluted the catalyst. We could also have performed more trials with different levels of water and catalyst. //