The effect of temperature on the reaction between Catalase and H2O2 Sarah AlShemesi
In this experiment we’ll be exploring the effects of temperature on the reaction between Catalase and H2O2.We’ll be using five different temperatures to test this. The five different temperatures will be 10, 30, 50, 70 and 90 oC. We will use the liver as a source of Catalase. A 1 gram piece of liver will be inserted into a test tube with 2 cm3 of water, then 2 cm3 of H2O2 will be added. The Catalase and H2O2 are expected to react and result in bubbles and a rise in the solution. If the bubbles form and the solution rises quickly then this suggests that the enzymes are working sufficiently and the nearing the optimum temperature.
What is the effect of the different temperatures 10 oC, 30 oC, 50 oC, 70 oC and 90 oC on the reaction between Catalase found in liver and H2O2 and what will be the Catalase’s optimum temperature?
* Independent variable: Temperature in oC
* Dependant variable: the height of the solution, measured with a ruler in cm. * Controlled variables: mass of liver, volume of water, volume of H2O2, method of pouring H2O2 into the liver/water solution. * The mass of the liver was controlled by measuring the liver pieces after they’ve been cut to ensure that each is 1 gram only. * Volume of water was controlled by measuring 2 cm3 using the same 10 cm3 measuring cylinder. * Volume of H2O2 was controlled by measuring 2 cm3 of it using the same 10 cm3 measuring cylinder. * The method of pouring the H2O2 into the liver/water solution was kept consistent by having the same person pour it in every time at the same approximate speed.
* H2O2 60 cm3
* 1 Ruler ( cm )
* Water 60 cm3
* 12 Test tubes
* 2 Tongue
* 2 Measuring cylinder 10 cm3
* 2 Droppers
* 1 Beaker 100 cm3
* A bowl of ice cubes
* 1 Knife
* 1 Bunsen Burner
* 1 Glass rod
* 1 Digital balance
* 3 Thermometers ( oC )
1. Cut the liver into twenty five pieces using the knife, use the digital balance to ensure that each piece of liver weighs 1 gram only. 2. Place each liver piece in an individual test tube.
3. Use the 10 cm3 measuring cylinder to measure 2 cm3 ( this amount of H2O was chosen so that when the H2O2 is added the solution can bubble and rise without spilling out of the test tube ) of H2O and add that amount of water to the test tube containing the piece of liver. 4. Place ice cubes at the bottom of the 100 cm3 beaker till the base of it is completely covered. 5. Place the previously mentioned test tube ( containing the water/liver solution) into the beaker holding it up at the center as you or your partner continue to fill the beaker with ice cubes till the test tube is completely submerged in ice and only the top is not. 6. Continuously measure the temperature of the solution.
7. When the solution reaches the temperature of 10 oC, remove the test tube from the beaker filled with ice and perform step 8 immediately. 8. Add 2 cm3 of H2O2, wait for the solution to react and for the bubbles to rise and then use your cm ruler to measure the height of the solution after it has risen and note the height down. 9. For the other trials you must heat your solution rather than cool it down. To do so, prepare your liver/water solution with the same dimensions as before. 10. Light up the Bunsen Burner to a soft flame.
11. Use the tongues to hold one test tube over the flame, you must move the test tube continuously to avoid burning or overheating and you must also measure the temperature of the solution continuously till it reaches the desired temperature for that trial; either 30 oC, 50 oC, 70 oC or 90 oC. 12. When the solution reaches the desired temperature quickly repeat step 8. 13. Repeat the procedure five times for each temperature to produce...