Lab 8 Activities Continued

Effect of pH on Peroxidase Activity

Overview

This activity will explore peroxidase activity at pH 3, 5, 7, and 10.

Additional Materials

In addition to the materials listed on Page 1, each lab group will need the following:

• pH 3 buffer
• pH 5 buffer
• pH 7 buffer
• pH 10 buffer

Method

Note: When adding the materials to the cuvette, always add the turnip extract LAST and place the cuvette in the spectrophotometer as quickly as possible. The reaction begins as soon as the extract comes in contact with hydrogen peroxide.

1. Set-up a cuvette for pH 3 by adding each material in the order listed below:
   • 10 drops 0.02% hydrogen peroxide
   • 5 drops 0.2% guaiacol
   • 20 drops of pH 3 buffer
   • 10 drops turnip extraction last
2. Secure the lid and quickly invert the cuvette to mix. Place the upright cuvette into the SpectroVis Plus.
3. Press “Collect” to begin recording data.
4. Stop data collection after 200s.
5. “Export Data” as a “.csv” file to computer or a USB flash drive.
   • Ensure that it has saved as a “.csv” file.
   • This will open in a text editor or spreadsheet.
6. Empty the contents of the cuvette into the trash beaker.
7. Thoroughly rinse the cuvette using the water bottle.
8. Sequentially repeat the experiment, exchanging the pH buffer with pH 5, 7, 10.

Make sure all group members are given an opportunity to save the data to their USB drive or make arrangements to have another student email them the data.

Effect of Temperature on Peroxidase Activity

Overview

This activity will explore peroxidase activity at 0°C, 20°C, 40°C, and 60°C.

Additional Materials

In addition to the materials listed on Page 1, each lab group will need the following:

• 0°C buffer
• 20°C buffer
• 40°C buffer
• 60°C 10 buffer

Method

Note: When adding the materials to the cuvette, always add the turnip extract LAST and place the cuvette in the spectrophotometer as quickly as possible. The reaction begins as soon as the extract comes in contact with hydrogen peroxide.

1. Set-up a cuvette for 0°C by adding each material in the order listed below:
   • 10 drops 0.02% hydrogen peroxide
   • 5 drops 0.2% guaiacol
   • 20 drops of 0°C buffer
   • 10 drops turnip extraction last
2. Secure the lid and quickly invert the cuvette to mix. Place the upright cuvette into the SpectroVis Plus.
3. Press “Collect” to begin recording data.
4. Stop data collection after 200s.
5. “Export Data” as a “.csv” file to computer or a USB flash drive.
   • Ensure that it has saved as a “.csv” file.
   • This will open in a text editor or spreadsheet.
6. Empty the contents of the cuvette into the trash beaker.
7. Thoroughly rinse the cuvette using the water bottle.
8. Sequentially repeat the experiment, exchanging the buffer with buffers at 20°C, 40°C, and 60°C.

Make sure all group members are given an opportunity to save the data to their USB drive or make arrangements to have another student email them the data.

Print this page