Investigating pH Effects on Catalase Activity

What is the primary function of catalase in the experiment?

At which pH level was the highest rate of oxygen production observed?

Why is it essential to repeat the experiment using different buffers?

What is the composition of the solution added to the boiling tube before observing the reaction?

What safety precaution should be taken during the experiment?

What does a buffer solution do in the context of this experiment?

What would likely happen to the rate of reaction if the pH were to drop significantly below 5?

What was the rate of oxygen production at pH 8?

Investigating the Effect of pH on Catalase Activity

Catalase is an enzyme that breaks down hydrogen peroxide (H₂O₂) into water (H₂O) and oxygen (O₂).
Buffer solutions resist changes in pH. Different solutions maintain different pH values.
Hydrogen peroxide is a metabolic product toxic to cells. Catalase protects cells by breaking it down.
Potato cells contain a high concentration of catalase.
A method was used to extract catalase from potato cells:
- A large potato was chopped small and placed into a blender with an equal amount of water.
- This mixture was blended to release the catalase from the potato cells.
- The potato debris settled to the bottom of the mixture.
- The liquid extract was removed.
The catalase extract's activity was then tested at different pH levels:
- Using a syringe, 5 cm³ of potato extract was placed in a boiling tube.
- 5 cm³ of a buffer solution (with a specific pH) was added to the boiling tube.
- The mixture was shaken to combine the extract and buffer solution.
- The mixture was left to settle for 5 minutes.
- 5cm³ of 5% hydrogen peroxide solution was added to the reaction mixture.
- A bung and delivery tube was placed in the boiling tube, connected to a beaker of water.
- The number of oxygen bubbles produced by the reaction per minute was counted.
The experiment was repeated using different pH buffers. The results are shown in a table with pH levels and the rate of reaction (measured in bubbles per minute).

This quiz explores the relationship between pH levels and the activity of the enzyme catalase, which breaks down hydrogen peroxide. You'll learn about the methods used to extract catalase from potato cells and how different buffer solutions affect its performance. Test your understanding of enzyme activity, pH influence, and the role of catalase in cellular protection.