Testing Enzyme Activity (Spectrometer)

Experiment #6C from Investigating Biology through Inquiry

• Identify variables, design and perform the investigation, collect data, analyze data, draw a conclusion, and formulate a knowledge claim based on evidence from the investigation.
• Determine the rate of the peroxidase catalyzed reaction converting H₂O₂ to H₂O and O₂.
• Gain increased understanding of factors affecting peroxidase activity.

Testing Catalase Activity (O₂ Gas Sensor)

Experiment #6A from Investigating Biology through Inquiry

In this Preliminary Activity, you will use catalase in yeast to catalytically decompose hydrogen peroxide. You will use an O₂ Gas Sensor to determine the rate of catalase activity by measuring oxygen gas produced as H₂O₂ is decomposed.

At the start of the reaction, there is no product, and the O₂ concentration is the same as the atmosphere. Shortly after data collection begins, oxygen accumulates at a rather constant rate. The slope of the curve at this initial time is constant and is called the initial rate. In this investigation, we will refer to this as the rate of catalase activity. As the peroxide is decomposed, less of it is available to react and the O₂ is produced at lower rates. When no more peroxide is left, O₂ is no longer produced. When data collection is complete, you will perform a linear fit on the resultant graph to determine catalase activity.

After completing the Preliminary Activity, you will first use reference sources to find out more about catalase, enzymes, and enzyme activity before you choose and investigate a researchable question dealing with catalase activity. Some topics to consider in your reference search are:

• catalyst
  
• enzyme
  
• catalase
  
• hydrogen peroxide
  
• collision theory
  
• reaction rate