Catalyzing Substrate Concentrations Ibraheem Murtaza, Neil Madadi, Autumn Coomes, Cameron Buckman, Allison Wright

Abstract We performed this experiment to determine if a hydrogen peroxide (H 2 O 2 ) concentration of 1.5% or 3% will catalyze faster. We used an enzyme catalase 2000 u/mL and 1.5% and 3% concentration of H 2 O 2. We believed that 3% H 2 O 2 concentration would catalyze faster, however, that is not what our results showed us. Our results showed that 1.5% H 2 O 2 concentration catalyzes faster. Research shows that 3% H 2 O 2 concentration does catalyze faster, therefore, we will need to do perform more trials to validate results.

Background Other research showed that 3.0% hydrogen peroxide catalyzed faster than 1.5% hydrogen peroxide due to the fact that higher concentrations are more reactive. We hypothesized that the 3.0% H202 concentration would catalyze faster than the 1.5%. After performing our designed experiment, we found that our hypothesis was incorrect. Although we designed our experiment based on those of other researchers, our results did not match the results of other identical experiments. That said, the fault was probably in some part of our experiment’s setup, whether it be a defective Vernier recorder or the presence of an unwanted substance in our flask. Our goal was to prove that 3.0% H202 catalyzed faster than 1.5% H202.

Hypothesis The Hydrogen Peroxide (H 2 O 2 ) concentration of 3% would catalyze faster than the 1.5 %H 2 O 2 concentration.

Materials Computer with Vernier Logger Pro software Labquest Mini Stirrer and stirring bar Ring stand Clamp 50 mL graduated cylinder 125 mL Erlenmeyer flask Vernier Pressure Sensor Luer-Lock tubing Rubber stopper Micropipette with clean tips 1.5% H 2 O 2 solution 3% H 2 O 2 solution Catalase 2000 u/mL Distilled water

Method Attach rod and clamp to stand. Attach clamp to 125 mL Erlenmeyer flask. Plug in stirrer and place under the flask. Connect Labquest Mini to Vernier Pressure Sensor and then connect to computer. Activate Vernier Logger Pro software on computer. Put 50 mL of 1.5% H 2 O 2 solution into flask. Using the micropipette, add 100 uL of catalase 2000 u/mL to flask. Add stir bar to flask. Seal flask with stopper and connect Luer-Lock tubing to Vernier sensor. Turn on stirrer to the 5 th speed and start date collection on computer for 200 seconds. Repeat steps with 3% H 2 O 2 solution.

Results The 1.5% concentration of Hydrogen Peroxide catalyzed at a faster rate because of the higher pressure created than the 3.5% concentration of Hydrogen Peroxide. The 1.5% concentration of Hydrogen Peroxide rose to a pressure of roughly 115 kPa before leveling out. The 3% concentration of H 2 O 2 rose to a pressure of 110 kPa before leveling out. The 1.5% concentration had a rate of kPa/sec, which is a higher catalyzing rate than the 3%, which had a rate of kPa/sec. Recorded for 200 seconds

1.5% Concentration of H202 with Catalase 2000 u/mL

3% Concentration of H202 with Catalase 2000 u/mL

Discussion The catalyzation of the hydrogen peroxide occurred faster during the experiment containing 1.5% H 2 O 2 rather than the 3% H 2 O 2. Opposite results. Some possible errors include: The pressure sensor connected to the laptop may have been leaking air out of a valve. We could run the experiment again and check to make sure no air is leaking. This may produce more accurate results.

Conclusion The data produced from the experiment disproved the hypothesis, more trials needs to be done to confirm that the 1.5% concentration of H 2 O 2 will catalyze faster than the 3% concentration of H 2 O 2.

Citations A Level Notes. (nd). Factors Affecting Enzyme Activity. [accessed 26 January 2014]. Retrieved from Enzyme-Activity/146?treehttp://alevelnotes.com/Factors-affecting- Enzyme-Activity/146?tree Worthington Biochemical Corporation. (nd). Introduction to Enzymes. [accessed 26 January 2014]. Retrieved from biochem.com/introbiochem/substrateconc.htmlhttp:// biochem.com/introbiochem/substrateconc.html