METHOD
1) The safety glasses were put on and the area was safe with full ventilation.
2) The potato was peeled using peeler before being cut into 6 cubes with the side of 5mm using a knife and chopping board.
3) 6 beakers were taken and marked 1 to 6 using a marker pen.
4) The 6 beakers were filled with water up to 10cm high and this was measured using a ruler. By adding some ice to the water, the temperature of beaker 1 was brought to 10°C and beaker 2 to 20°C. Using the hot plate, the temperatures of the water in beakers 3 to 6 were brought to 30°C, 40°C, 50°C and 60°C. The temperature was measured using a thermometer.
5) 6 test tubes were then taken and marked 1 to 6 using a marker pen.
6) The test tubes were then marked with a line 2cm from the bottom of the tube. The hydrogen peroxide solution was poured into the 6 test tubes up to the level of the line.
7) Each test tubes were placed in a different beaker for 5 minutes, to enable the hydrogen peroxide to stabilize at the same temperature.
8) The potato that was cut into small pieces was placed into test tube 1 using tongs. As soon as the potato was placed into the test tube, the stopwatch was started.
9) The stopwatch was stopped after 5 minutes and the height of the bubbles was recorded using a ruler.
10) Steps 8, 9 and 10 were repeated with different test tubes.
11) The experiment was repeated 5 times and the average of was taken.
1) The safety glasses were put on and the area was safe with full ventilation.
2) The potato was peeled using peeler before being cut into 6 cubes with the side of 5mm using a knife and chopping board.
3) 6 beakers were taken and marked 1 to 6 using a marker pen.
4) The 6 beakers were filled with water up to 10cm high and this was measured using a ruler. By adding some ice to the water, the temperature of beaker 1 was brought to 10°C and beaker 2 to 20°C. Using the hot plate, the temperatures of the water in beakers 3 to 6 were brought to 30°C, 40°C, 50°C and 60°C. The temperature was measured using a thermometer.
5) 6 test tubes were then taken and marked 1 to 6 using a marker pen.
6) The test tubes were then marked with a line 2cm from the bottom of the tube. The hydrogen peroxide solution was poured into the 6 test tubes up to the level of the line.
7) Each test tubes were placed in a different beaker for 5 minutes, to enable the hydrogen peroxide to stabilize at the same temperature.
8) The potato that was cut into small pieces was placed into test tube 1 using tongs. As soon as the potato was placed into the test tube, the stopwatch was started.
9) The stopwatch was stopped after 5 minutes and the height of the bubbles was recorded using a ruler.
10) Steps 8, 9 and 10 were repeated with different test tubes.
11) The experiment was repeated 5 times and the average of was taken.
RELIABILITY AND VALIDITY
Reliability
1) The experiment was repeated with different temperatures to get reliable results.
2) Experiment was repeated 5 times to get the average results and thus, making the experiment reliable.
3) The results match with what the scientists say about the activity of enzyme catalase.
4) The experiment was reliable as the results were close together even when the experiment was repeated.
5) One factor that was not reliable was that the results were different each time, this is probably because of human errors in recording or whilst undertaking the actual experiment.
6) The stopwatch was used, instead of estimate, to get the accurate results.
7) Instead to taking the values for each trial, an average was taken.
8) There are no outliers, which proves the reliability of the experiment.
9) Results were consistent.
10) During repetition, beakers and test tubes were washed each time to ensure nothing is left behind.
11) Hydrogen peroxide was poured into the same type of test tube to be accurate and reliable. The size was also the same.
12) The same person was measuring and recording the substances to get reliable results.
Validity
1) All the variables were kept constant except the temperature.
2) A control was set up.
3) The same samples of potatoes were used for each experiment.
4) The experiment was performed at the same temperature.
5) The same apparatus was used for the repeated steps of the experiment.
6) The person who recorded the results, added the enzyme etc. was the same.
There are a lot of factors that make my experiment reliable and valid and they are listed above. Although, there are also some factors that are not reliable, but most of them are reliable and that makes my experiment reliable and valid.
RESULTS
Please see attached documents for the result tables, images and graphs.
Reliability
1) The experiment was repeated with different temperatures to get reliable results.
2) Experiment was repeated 5 times to get the average results and thus, making the experiment reliable.
3) The results match with what the scientists say about the activity of enzyme catalase.
4) The experiment was reliable as the results were close together even when the experiment was repeated.
5) One factor that was not reliable was that the results were different each time, this is probably because of human errors in recording or whilst undertaking the actual experiment.
6) The stopwatch was used, instead of estimate, to get the accurate results.
7) Instead to taking the values for each trial, an average was taken.
8) There are no outliers, which proves the reliability of the experiment.
9) Results were consistent.
10) During repetition, beakers and test tubes were washed each time to ensure nothing is left behind.
11) Hydrogen peroxide was poured into the same type of test tube to be accurate and reliable. The size was also the same.
12) The same person was measuring and recording the substances to get reliable results.
Validity
1) All the variables were kept constant except the temperature.
2) A control was set up.
3) The same samples of potatoes were used for each experiment.
4) The experiment was performed at the same temperature.
5) The same apparatus was used for the repeated steps of the experiment.
6) The person who recorded the results, added the enzyme etc. was the same.
There are a lot of factors that make my experiment reliable and valid and they are listed above. Although, there are also some factors that are not reliable, but most of them are reliable and that makes my experiment reliable and valid.
RESULTS
Please see attached documents for the result tables, images and graphs.
results,_images_and_graphs.pdf | |
File Size: | 552 kb |
File Type: |