Name: Simon SohnGroup members: Misaki, HirokiDate of experiment: Dec. 6th 2010 Factors affecting the speed of a catalase reaction <Concentration of the substrate>Aim: To see if the concentration of the hydrogen peroxide can affect the speed of thecatalase reactionHypothesis: The higher concentration of the hydrogen peroxide, the faster the speed ofthe catalase reaction. Thus, more oxygen will be produced during the reaction. This willhappen because more substrates will be there in higher concentration of hydrogenperoxide, which are to be broken down by the enzyme in liver.Variables: Input variable: The concentration of the hydrogen peroxide. I will change it byusing 0.5%, 1% and 1.5% hydrogen peroxide in the experiment. Output variable: The amount of oxygen produced in the catalase reaction. I willmeasure the total amount of the solution (H202+liver+foam). Control variables: Control variable 1: The amount of liver. I will keep it the same by using the exact same amount of liver by measuring its weight. Control variable 2: The temperature of the hydrogen peroxide. I will keep it the same by keeping the same temperature in the place where the experiment is conducted. Control variable 3: The type of liver. I will keep it the same by using the same type of liver. (Chicken liver) Control variable 4: The length of time needed for measuring the catalase reaction. I will keep it the same by measuring every reaction for 1 minute. Control variable 5: The amount of the hydrogen peroxide. I will keep it same by using the exact same amount of hydrogen peroxide in each trial. (20ml)
Materials: • 150ml of 0.5% hydrogen peroxide • 150ml of 1.0% hydrogen peroxide • 150ml of 1.5% hydrogen peroxide • 45g of liver • 100ml Measuring Cylinder (x1) • Stopwatch (x1) • Electronic Balance (x1) • Tweezer (x1) • Scalpel (x1) • Dissecting Dish (x1) • Lab coat (x1)Method: 1. Cut the liver into smaller pieces with scalpel and dissecting dish. 2. Measure 5g of liver by using electronic balance. 3. Pour 50ml of 0.5% hydrogen peroxide to cylinder. 4. Put 5g of liver into the cylinder. 5. Measure and record the total amount of solution (H202+liver+foam) after 1 minute by using a stopwatch. 6. Repeat the method 1-5 twice. 7. Repeat the method 1-5 three times using 1% hydrogen peroxide instead of 0.5% hydrogen peroxide. 8. Repeat the method 1-5 three times using 1.5% hydrogen peroxide instead of 0.5% hydrogen peroxide. Data Table: Total amount of the solution (H2O2+liver+foam) (ml)H2O2Concentration(%) Trial 1 Trial 2 Trial 3 Average 0.5 29.0 30.0 30.0 29.7 1.0 35.0 37.0 35.0 35.7 1.5 45.0 40.0 38.0 41.0
Graph: H202 Concentra.on .vs. Amount of Oxygen Produced (Average) 50.0 Total amount of the solu.on (H2O2+liver+foam) (ml) 40.0 30.0 20.0 10.0 0.0 0.0 0.5 1.0 1.5 2.0 H2O2 Concentra.on (%) Conclusion: As it can be seen in the table above, the higher concentration of H202 resulted inmore total amount of solution including H202, liver and foam. My data is reliablebecause all the trials in each concentration show increasing total amount, as theconcentration of hydrogen peroxide gets higher. Moreover, the difference betweenaverage values of all three concentrations is 6. Thus, my hypothesis “The higherconcentration of the hydrogen peroxide, the faster the speed of the catalase reaction”was correct. The higher concentration results in the faster the speed of the catalasereaction because increasing concentration of substrate in higher concentration of H2O2increases the chances of substrates to join with enzyme. Thereby, in my case, moreoxygen foam is created in the reaction.Evaluation:Errors/Weaknesses in Specific Effect on Improvement to yourYour Method Your Data method
1. In the beginning of the The difference We used 20ml ofexperiment, we used between each hydrogen peroxide50ml of hydrogen concentration didn’t instead of 50ml ofperoxide for each trial. vary much. Therefore, hydrogen peroxide andHowever, 50ml of we couldn’t get any this gave the obvioushydrogen peroxide was pattern or trend. difference of amount oftoo much to see the oxygen produceddefinite difference between eachbetween each concentration.concentration.2. Livers were cut into Some trials, in which Cutting the liver into asdifferent size of pieces. comparatively small same size of pieces asThis created more pieces of liver were possible in order tosurface area of liver in put into H2O2, would create same surfacecertain trials. In the result in more oxygen area of the liver.certain trials, the speed produced. In ourof catalase reaction case, the total amountcould get faster. of solution would be higher.3. Livers often stuck to When livers stuck to Waiting till liverthe cylinder. It took more the cylinder, it often completely sinks intotime for liver to be sunk resulted in less H2O2, and then startinginto H202. oxygen produced in the timing. that trial. This error reduced the reliability of the data.Other areas of investigation:If I get to do this experiment over, I want to change the input variable to different type oforgan. This is because if I use different type of organ as my input variable, thisexperiment will give entirely different hypothesis and pattern from previous experimentwith different concentration of hydrogen peroxide. Therefore, I would obtain entirely newscientific information.