Ib Bio Experiment on Effect of Substrate Conc on Enzyme Activity

Practical Assessment 2 The effect of substratum submerging on the outrank of enzyme activity of Catalase Aim To investigate the effect of substrate assiduity (manipulated by increasing concentration of heat content bl apiece) on the rate of enzyme activity of catalase, produced by liver-colored cells, on the decomposition of total heat hydrogen bl for each one. introduction Enzymes atomic number 18 biological catalysts that increase the rates of chemical reactions.In an enzyme-catalyzed reaction, the substrate binds to the active web site and forms enzyme-substrate complex with the enzyme through the lock and bring up method (where the lock represents the enzyme and the key represents the substrate). The enzyme then breaks the bonds in the substrate. The product of the reaction then leaves the enzyme, which delays self kindred(prenominal)(predicate) after the reaction. Without enzymes, many essential processes, such as digestion, would occur to a fault slowly f or life to continue.Catalase is an enzyme produced by our liver cells to break down henry peroxide a common end product of metabolism, but passing toxic to tissues if accumulated in the body into water and atomic number 8. The equation of the reaction is as follows 2 H2O2 O2 + 2 H2O Catalase Catalase In this experiment, we obtain 6% heat content peroxide origin from a pharmacy and extract sui gameboard concentrations of catalase from liver cells.Filter write up magnetic magnetic discs atomic number 18 dipped into the catalase solution before they are submerged in heat content peroxide solution. The oxygen produced from the enzyme reaction impart form on the discs and cause the disc to be buoyant enough to screw up upwards. We can investigate the effects of substrate concentration on the rate of reaction by catalase by victimization different concentrations of hydrogen peroxide solution, and measuring the rate of reaction by measuring measure taken for the disc to float to the surface when sufficient oxygen is produced. HypothesisThe possibility for this experiment is that the rate of reaction leave increase with the increase of hydrogen peroxide concentration, if the other factors of enzyme activity (such as temperature, pH and enzyme concentration) are kept constant. However, the rate of reaction will stop increasing with hydrogen peroxide concentration at a point where the enzyme concentration becomes a restrict factor. At high substrate concentrations, most of the active sites available are occupied since they are saturated with substrate molecules at any given time.Hence, a further increase in substrate concentration will not cause the rate of decomposition of hydrogen peroxide to increase. As such, the expected graph from this experiment is as follows Graph 1 judge graph of rate of reaction against concentration of substance Variables Dependent variant regulate of enzyme activity of catalase in terms of time taken for the magne tic disk to float to the surface of the hydrogen peroxide solution when sufficient oxygen is produced. * Once the pervade theme disc has r distributivelyed the bottom of the adjudicate thermionic tube, the stop watch is started.The stopwatch is stopped once the disc has r severallyed the surface of the hydrogen peroxide solution. The recorded measure indicates the amount of time taken for the disk to float to the surface of the hydrogen peroxide solution. Independent variable Concentration of hydrogen peroxide solution. * Add different volumes of water to the different volumes of 6 % hydrogen peroxide solution. Controlled variable(s) 1. Enzyme concentration * We are provided with homogenous liquid liver solution. Hence, the concentration of catalase is constant throughout the liquid liver solution. . Volume of hydrogen peroxide solution * The volume of hydrogen peroxide solution in each test tube is 5cm3. Controlling the volume of hydrogen peroxide solutions ensures that the s ame amount of hydrogen peroxide molecules (substrates) is available for reaction in the test tube. 3. Size of test tubes * The test tubes used each time must be of the same size, length and volume. This is to ensure that the distance the filter paper disc has to travel (between the bottom of the test tube to the surface) is the same for each time. 4. Filter paper disc The filter paper discs should be of the same diameter and of the same thickness. This is to ensure that the same amount of oxygen burn out is required to lift it to the surface each time thereby enabling us to determine the time taken for it to do so. 5. Temperature * Enzyme activity is touch on by temperature. The experiment is carried out in room temperature (25 C), which is assumed to remain constant throughout the duration of the experiment. Apparatus * Digital stop watch, right to 0. 01 s * 6 Test tubes (Same size and length) * 6 Test tube holders * Wooden stick * 500 cm3 beaker 6 measuring cylinders Material s * 6 % hydrogen peroxide solution provided by teacher * Homogenous liquid liver solution provided by teacher * 30 Filter paper discs provided by teacher * Distilled water Procedure 1. 0. 75 % hydrogen peroxide solution is prepared by measuring 3. 00 cm3 of 6 % hydrogen peroxide using a measuring cylinder and then diluting it with 21. 00 cm3 of distilled water. 1. 50 %, 3. 00 %, 4. 50 % and 6. 00 % hydrogen peroxide solutions are prepared using the same method with interchangeable volumes of 6 % hydrogen peroxide and water as shown in the table below.Concentration of hydrogen peroxide solution/ %( 0. 02) Volume of 6 % hydrogen peroxide/ cm3( 0. 01) Volume of water added/ cm3( 0. 01) 0. 75% 3. 00 21. 00 1. 50% 6. 00 18. 00 3. 00% 12. 00 12. 00 4. 50% 18. 00 6. 00 6. 00% 24. 00 0. 00 Table 1 Dilution table for preparing different concentrations of hydrogen peroxide solutions The prepared hydrogen peroxide solutions are poured into test tubes. Each test tube should contain 5 cm3 of the solution. The test tubes with their olutions are placed in the test tube holder, labeled with the concentration of hydrogen peroxide solution that they contain. 2. Obtain homogenous liver liquid from teacher and add 8 cm3 of liver liquid into each petri dish to be used in the experiment. (5 petri dishes) 3. A filter paper disc is soaked with liver liquid in each petri dish. 4. A filter paper disc is removed from petri dish and pushed to the bottom of a test tube with 0. 75 % hydrogen peroxide solution using a wooden stick. 5. The stopwatch is started immediately when the filter paper disc touches the bottom of the test tube. . The stop watch is stopped once the filter paper disc reaches the surface. The time taken for the filter paper disc to float to the surface is recorded. 7. Steps 3 6 are perennial a further 5 times, using other new 0. 75 % hydrogen peroxide solutions. 8. The average of the 6 readings for each hydrogen peroxide concentration is calculated and recorded. Th e rate of reaction is calculated by the avocation formula Rate of reaction = 1/Average time taken for filter paper disc to reach the surface of the hydrogen peroxide solution from the bottom 9.Steps 3-7 are repeated with 1. 50 %, 3. 00 %, 4. 50 % and 6. 00 % hydrogen peroxide solutions 6 times each. Data table Timing for each run conducted/s Concentration of Hydrogen Peroxide solution/% 1 2 3 4 5 6 Average timing for each concentration Hydrogen Peroxide solution/s Rate of reaction for each concentration Hydrogen Peroxide solution/s 0. 75% 1. 50% 3. 00% 4. 50% 6. 00%