Catalase is an enzyme found in plants and other organisms that catalyzes the decomposition of hydrogen peroxide (H2O2) into water and oxygen. Catalase activity can be measured in plant leaves by monitoring the rate of oxygen production.
Materials:
* Fresh plant leaves
* Hydrogen peroxide (H2O2) solution (3%)
* Glass test tubes
* Stoppers
* Graduated cylinder
* Stopwatch
* Safety goggles
Procedure:
1. Collect several fresh plant leaves.
2. Cut the leaves into small pieces using a sharp knife or scissors.
3. Place 5 g of leaf tissue in a glass test tube.
4. Add 10 mL of 3% hydrogen peroxide solution to the test tube.
5. Quickly stopper the test tube and start the stopwatch.
6. Observe the amount of time it takes for the leaf tissue to produce enough oxygen to completely fill the test tube.
7. Record the time in seconds.
Calculations:
The catalase activity of the leaf tissue can be calculated using the following formula:
Catalase activity = (Volume of oxygen produced in mL)/(Time in seconds)
Example:
If the leaf tissue produces 10 mL of oxygen in 30 seconds, then the catalase activity would be:
Catalase activity = (10 mL)/(30 s) = 0.33 mL/s
Interpretation:
The catalase activity of plant leaves can vary depending on the species of plant, the age of the leaves, and the environmental conditions. In general, higher catalase activity is associated with greater resistance to oxidative stress.
Safety Precautions:
* Wear safety goggles to protect your eyes.
* Hydrogen peroxide is a corrosive substance. Handle it with care and avoid contact with your skin and clothing.
* If hydrogen peroxide comes into contact with your skin or eyes, flush with water immediately.