Why do I need to control these?
To ensure a fair test is carried out. The temperature is very important when dealing with enzymes because enzymes work best at a certain temperature, when the temperature is too high enzymes are denatured and so the experiment wouldn’t work.
Volume of pectinase and amount of apples have to be kept the same because if more pectinase was added more juice would be produced and vice versa. The amount of apple has to be kept the same because it is the substance that the pectinase is working on.
- Apples need to be the same size
- Temperature must be kept the same
- Same volume of pectinase must be used.
List of Equipment
- Apple
- Water bath
- White tile
- Test tubes
- Knife
- Stop watch
- Water
- Measuring cylinder
- Filter paper
- Pectinase
- Spatula
- Thermometer
- Glass stirring rod
Safety
- Wear safety goggles
- Wear a lab coat
I will wear safety goggle to protect my eyes in case any pectinase splashes in them. I will also wear a lab coat to protect my skin and clothes from any chemicals. I will move any obstructing and unnecessary objects to prevent any accidents, like tripping over a bag.
Method
I first place a piece of apple on a white tile. Then I cut it into small chunks. Next I put these chunks into a blender, which will produce a soluble mash. I then add 5 grams of the mashed up apple into a test tube. Then the one test tube I add 2cm³ of pectinase. Then into a second test tube I add 5 grams of the mashed up apple and with it I put 2cm³ of water. I next place the test tubes into a hot water bath for ten minutes. After ten minutes I remove the test tubes from the hot water bath and empty the contents into two separate measuring cylinders with funnels and filter paper on top. I then leave them to stand for ten minutes. After the 10 minutes I measure how much juice has been produced in each measuring cylinder. I put these results into a table.
Results of Experiment
Volume of juice collected in (cm³)
At 40° Incubation time 10 minutes.
Obtaining Evidence
When I carry out my investigation I must clearly record my results. And remember to use headings and units.
My results do vary slightly. I could carry out the experiment again incase the first experiment wasn’t fair.
I think I have done enough measurements to confirm my prediction. But the more measurements I take the more accurate I can be.
There are other ways for me to display my results for example in a graph or bar chart.
Conclusion
The results of my experiment support my hypothesis very strongly. My hypothesis was that the mashed up apple with added pectinase would produce more juice than the mashed up apple with added water. This prediction was correct because pectinase is an enzyme used to make fruit juices. The pectinase acts on the pectin in the apple, which holds the cell walls of the fruit together, and they begin to deteriorate which produces the juice.
Evaluation
Problems with equipment: I was unable to use a proper hot water bath so instead I had to use a beaker and keep refilling the beaker with hot water so it was a steady 40°. This meant that it wasn’t constantly at the correct temperature.
Possible Inaccuracies: The fact that I didn’t have access to a hot water bath meant that the temperature of the water would have been inaccurate at times.
Anomalous Results: I did not have any anomalous results.
Improvements: I could do the experiment again and collect more results. I could record the amount of juice every minute rather than every 10 minutes. This way I could have a more accurate understanding of the result of my experiment. If I did the experiment again I could use a hot water bath, that way my results would be a lot more accurate.