Difference between revisions of "GCSE Biology Required Practical: Enzyme Rates of Reaction"
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Investigate the effect of [[pH]] on the rate of reaction for an [[enzyme]]. | Investigate the effect of [[pH]] on the rate of reaction for an [[enzyme]]. | ||
| − | === | + | ===Experiment Version 1=== |
| + | ====Variables==== | ||
*[[Independent Variable]] - [[pH]] of the buffered [[pH]] [[solution]]. | *[[Independent Variable]] - [[pH]] of the buffered [[pH]] [[solution]]. | ||
*[[Dependent Variable]] - Time taken for the colour change to take place. | *[[Dependent Variable]] - Time taken for the colour change to take place. | ||
*[[Control Variable]]s - The temperature of all solutions. The volume of all solutions. | *[[Control Variable]]s - The temperature of all solutions. The volume of all solutions. | ||
| − | + | ====Method==== | |
#Place test tubes containing amylase solution, starch solution and a range of [[pH]] buffer solutions from [[pH]] 1-13 in a water bath at a temperature of 25°C and wait until all [[solution]]s reach that temperature. | #Place test tubes containing amylase solution, starch solution and a range of [[pH]] buffer solutions from [[pH]] 1-13 in a water bath at a temperature of 25°C and wait until all [[solution]]s reach that temperature. | ||
#Use a pipette to place one drop of Iodine Solution into each depression in a spotting tile. | #Use a pipette to place one drop of Iodine Solution into each depression in a spotting tile. | ||
Revision as of 09:40, 11 April 2019
Key Stage 4
Meaning
Investigate the effect of pH on the rate of reaction for an enzyme.
Experiment Version 1
Variables
- Independent Variable - pH of the buffered pH solution.
- Dependent Variable - Time taken for the colour change to take place.
- Control Variables - The temperature of all solutions. The volume of all solutions.
Method
- Place test tubes containing amylase solution, starch solution and a range of pH buffer solutions from pH 1-13 in a water bath at a temperature of 25°C and wait until all solutions reach that temperature.
- Use a pipette to place one drop of Iodine Solution into each depression in a spotting tile.
- Use a clean pipette to place 2cm3 of each pH buffer into seperate depressions of the spotting tile, ensuring the pipette is rinsed each time to prevent contamination.
- Use a clean pipette to place 2cm3 of starch solution into a depression on the spotting tile.
- Time how long it takes for the colour to turn from blue-black to orange.
- Repeat steps 4 and 5 until all pH buffers have been tested.
- Plot a graph with pH on the x-axis and time taken on the y-axis.