Catechol Oxidase Lab

Name: Prakash Bhandari
Lab Report Title: Effect of pH on Enzyme Activity
Purpose:

This lab exercise is intended to study about PH affect the enzymatic reaction. Enzymes activity rates are affected by temperature, pH, and the presence of any inhibitors or activators. The purpose of this experiment was to determine the pH range and optimum pH for catechol oxidase to catalyze the reaction to form benzoquinone, detected using the 0-5 color intensity scale from Table 1.

Hypothesis:
My hypothesis for this experiment will show that the optimum pH will be 7, and very low pH will denature the enzymes.

Materials:
1. 6 Test Tubes
2. Test Tube Rack
3. Metric Ruler
4. China Maker
5. pH Buffers (2,4,6,7,8,10)
6. Potato extract with catechol oxidase
7. 1% catechol
8. Water bath

Test method:
In this

Clean and dry all test tubes.
2. Set water bath 40oC temperature.
3. Level test tubes with the number 2,4,6,7,8, and10 for initials identification.
4. Take matrix ruler and lay test tubes and mark from the bottom at 4cm, 5cm and 6cm
5. Fill each test tubes to the 4-cm mark with the respective pH buffer (2,4,6,7,8, and 10)
6. Add more 1cm (up to 5 cm mark) of potato extract containing catechol oxidase and swirl to mix.
7. Add more 1cm (up to 6cm mark) catechol and swirl to mix.
8. Record the color intensity (0-5) of each in “color intensity 0 min” column of table 1.
9. Place the test tubes in the 400C water bath for 10 minutes, swirling occasionally to mix.
10. Removed after 10 minutes from the 40oC water bath. Record the color intensity (0-5) of each test tubes in “Color Intensity 10 min” column of table 1.
Observations:
The contain of each test tube has different pH buffer. Each test tubes. After observation, I found some difference between before and after 10 min in temperature. After 10 min 40oC temperature. I found same color intensity in test tubes 2 and 4. Test tubes 6 and 10 has orange yellow color and 7, 8 test tubes have rise-brown