Difference between revisions of "GCSE Biology Required Practical: Enzyme Rates of Reaction"
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==Key Stage 4== | ==Key Stage 4== | ||
| + | {{#ev:youtube|https://www.youtube.com/watch?v=8Yqbu56ImXk}} | ||
===Meaning=== | ===Meaning=== | ||
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]]. | ||
| Line 9: | Line 10: | ||
*[[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==== | ====Method==== | ||
| − | #Place test tubes containing | + | #Place [[Test Tube|test tubes]] containing a range of of [[pH]] [[Buffer Solution|buffer solutions]], a container of [[starch]] [[solution]] and a container of [[amylase]] [[solution]] in a water bath at a [[temperature]] of around 30°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|spotting tile]]. |
| − | #Use a clean pipette to place 2cm<sup>3</sup> of each [[pH]] buffer into | + | #Use a clean [[pipette]] or [[syringe]] to place 2cm<sup>3</sup> of each [[pH]] buffer into a [[Test Tube|test tube]]. |
| − | #Use a clean pipette to place | + | #Use a clean [[pipette]] or [[syringe]] to place 2cm<sup>3</sup> of starch solution into the same [[Test Tube|test tube]]. |
| − | # | + | #Use a clean [[pipette]] or [[syringe]] to place 1cm<sup>3</sup> of [[amylase]] [[solution]] into the same [[Test Tube|test tube]] and start the [[stopwatch]]. |
| − | #Repeat steps | + | #Use a clean [[pipette]] to remove a drop of the [[solution]] form the [[Test Tube|test tube]] and drop it on the spotting tile every 10 seconds, beginning at 0 seconds. |
| + | #Repeat this until the [[Iodine Solution|iodine solution]] in one of the depressions no longer turns black, but instead remains orange. | ||
| + | #Repeat steps 2 to 7 until all different [[pH]] buffers have been tested. | ||
#Plot a graph with [[pH]] on the x-axis and time taken on the y-axis. | #Plot a graph with [[pH]] on the x-axis and time taken on the y-axis. | ||
| + | ===References=== | ||
| + | ====Edexcel==== | ||
| + | :[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Biology core practicals; pH and enzymes, pages 18-19, GCSE Combined Science, Pearson Edexcel ''] | ||
Latest revision as of 14:25, 2 November 2019
Contents
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 a range of of pH buffer solutions, a container of starch solution and a container of amylase solution in a water bath at a temperature of around 30°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 or syringe to place 2cm3 of each pH buffer into a test tube.
- Use a clean pipette or syringe to place 2cm3 of starch solution into the same test tube.
- Use a clean pipette or syringe to place 1cm3 of amylase solution into the same test tube and start the stopwatch.
- Use a clean pipette to remove a drop of the solution form the test tube and drop it on the spotting tile every 10 seconds, beginning at 0 seconds.
- Repeat this until the iodine solution in one of the depressions no longer turns black, but instead remains orange.
- Repeat steps 2 to 7 until all different pH buffers have been tested.
- Plot a graph with pH on the x-axis and time taken on the y-axis.