THE EFFECT OF TEMPERATURE ON CATALASE
What is the effect of various temperatures, 0°C, room temperature, 37°C, 50°C, 60°C, on the number of oxygen gas bubbles liberated, in a decomposition reaction between the enzyme Catalase, obtained from crushed mung beans, and 2% of the substrate Hydrogen Peroxide? INTRODUCTION:
Enzymes are biological catalysts that increase the rate of chemical reactions without they themselves being involved in the reaction itself. Enzymes are proteins that have a 3-Dimesional shape and contain a region called the active site to which only a specific substrate binds to, structurally. In this experiment, the enzyme Catalase will be used. Catalase is commonly found in animal and plant cells (but a significant amount is found in mung beans), and plays a fundamental role in the human body by catalyzing Hydrogen Peroxide, which is a poisonous waste product, into harmless products of Water and Oxygen gas. 2H2O2 ====== 2H2O + O2
This experiment will investigate the effect of temperature on the rate of catalase activity by measuring the number of oxygen gas bubbles produced. HYPOTHESIS:
For a reaction to occur, particles must collide with sufficient enough energy to break the existing bonds and form new ones. As temperature increases, so will the kinetic energy of the Hydrogen peroxide and catalase molecules. This means that the molecules are moving faster. Faster movement of the reacting molecules would increase the frequency of collisions and thus, increase the number of effective collisions taking place. As a result, more oxygen gas would be produced as the rate of reaction has increased. Rate of reaction is directly proportional to the temperature until the optimum temperature has been reached, after which the enzyme denatures, meaning the shape of the enzyme has irrevocably changed so that the substrate can no longer fit into the active site, resulting in an extremely slowed down/stopped reaction. Since Catalase is found in humans, it should function best at the temperature of the human body, which is 37°C.
METHOD TO CONTROL
Temperature of the catalase and the mung beans.
Both of them will each be put in a test tube and either cooled or heated to the desired temperature intervals, with the heating done by a water bath and the cooling done by using melting ice. DEPENDENT
Number of bubbles produced.
Amount and concentration of Hydrogen peroxide.
Using the same pipette, all trials will use 10cm3 of the same Hydrogen peroxide solution.
Amount of Mung beans
Each trial will use exactly 15g of the same pre-prepared mung beans.
Each trial will be carried out for exactly the same amount of time of 2 minutes, started immediately, when the mung beans are dropped into the Hydrogen peroxide.
All of the test tubes used in the experiment will be of the same type, i.e, be of the same length and size, so as to obtain accurate results.
All the beans used in each trial, are obtained from the original prepared beans and hence, will all have the same PH.
300g of crushed, soaked mung beans.
250cm3 of 2% Hydrogen peroxide solution.
Thermometer +/- 0.05°C.
Delivery tube with 2 corks.
Bowl of Ice.
15 test tubes (Or 3 test tubes, washed thoroughly between trials) Test tube stand.
Digital Stopwatch +/- 0.005s.
Pestle and mortar.
PREPARATION OF THE MUNG BEANS
1. 300g of mung beans were soaked overnight .
2. The beans were then crushed evenly. This is the source of Catalase in this experiment. REACTION IN THE COLD WATER BATH
3. Two dry, clean, test tubes were taken. One was filled with 10cm3 of Hydrogen peroxide and the other was filled with 5 4. g of the mung beans.
5. Another test tube was filled 3/4 with water for use later. 6. Both the...
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