If you wanted to figure out what the optimum temperature is for catalase, how would you set up an experiment? Answer the following questions to explain the setup.

 

1 what is the independent variable?

2 what is the dependent variable?

3 what will be the negative control? 

• list what one will put into the negative control tube.

4 there will be 3 experimental tubes. What will they be?

a)list what one will put into each tube

5 how will one treat each tube - how will the experiment work?

a)write step by step directions to complete the experiment.

6 how will you know what the optimum temperature is from your results?

1. Different Temperatures

2. Catalase (enzyme) activity

3. In a negative control tube, put the following:

-catalase enzyme only 

(place at room temperature only)

 

*note that there is no substrate for the enzyme. This is a negative control and we do not want an enzyme activity to be recorded in this setup, thus, we remove the substrate so that there is no substance that the catalase can act upon.

 

4. there will be 3 experimental tubes. What will they be?

List what one will put into each tube

In the 1^st experimental tube, put the following:

-5 mL hydrogen peroxide

-1 mL catalase enzyme 

Place solution in 35 degrees Celsius setup

 

In the 2^nd experimental tube, put the following:

-5 mL hydrogen peroxide

-1 mL catalase enzyme 

Place solution in 37 degrees Celsius setup

 

In the 3^rd experimental tube, put the following:

-5 mL hydrogen peroxide

-1 mL catalase enzyme 

Place solution in 39 degrees Celsius setup

 

*Note: You can change the volume of hydrogen peroxide and catalase enzyme, as long as they are kept constant or equal in three experimental setups. We do not want this to affect the results of the experiment. Only the temperatures should be different in the three setups. 

 

5.See the explanation tab for the detailed step by step.

 

6. The temperature in the setup with the lowest hydrogen concentration is the optimum temperature. See explanation tab for the explanation.

Step-by-step explanation

1 what is the independent variable?

Independent variables should be the different temperatures because we are investigating at which optimum temperature will catalase works best. Thus, you can have 3 to 6 different temperatures to investigate with 2-degree Celsius interval with each other. Since Catalase is an enzyme in living organisms, we can estimate our temperatures near 37 degrees celsius. The following temperatures can be used as independent variables:  35 deg. C, 37 deg. C, 39 deg. 

 

2.Catalase Activity. Since we are looking for the best temperature in which catalase works best, then we need to determine in which temperature does the catalase activity highest. Catalase's function is to convert hydrogen peroxide into water and oxygen. To determine the activity of catalase, we can determine the amount of hydrogen peroxide that remained after the reaction. The higher the hydrogen peroxide, the lower the activity because it means that the catalase is not doing its function well and no enzyme activity happened. If the hydrogen peroxide concentration is low, then it means that the catalase activity is high because all of the hydrogen peroxides is converted into water and oxygen, thus its activity is high. In the experiment, we need to find at which temperature does catalase activity the highest (in terms of low hydrogen peroxide concentration.

 

3. what will be the negative control? 

• list what one will put into the negative control tube.

In a tube, put the following:

-catalase enzyme only 

place at room temperature only

 

*note that there is no substrate for the enzyme. This is a negative control and we do not want an enzyme activity to be recorded in this setup, thus, we remove the substrate so that there is no substance that the catalase can act upon.

 

4. there will be 3 experimental tubes. What will they be?

List what one will put into each tube

 

In the 1^st experimental tube, put the following:

-5 mL hydrogen peroxide

-1 mL catalase enzyme 

Place solution in 35 degrees Celsius setup

 

In the 2^nd experimental tube, put the following:

-5 mL hydrogen peroxide

-1 mL catalase enzyme 

Place solution in 37 degrees Celsius setup

 

In the 3^rd experimental tube, put the following:

-5 mL hydrogen peroxide

-1 mL catalase enzyme 

Place solution in 39 degrees Celsius setup

 

*Note: You can change the volume of hydrogen peroxide and catalase enzyme, as long as they are kept constant or equal in three experimental setups. We do not want this to affect the results of the experiment. Only the temperatures should be different in the three setups. 

 

 

5. how will one treat each tube - how will the experiment work?

• write step-by-step directions to complete the experiment.

Step 1: Label 4 Tubes with each of the following:

Tube 1: Negative control (Catalase enzyme only)

Tube 2: Catalase + Hydrogen Peroxide in 35 degrees Celsius

Tube 3: Catalase + Hydrogen Peroxide in 37 degrees Celsius

Tube 4: Catalase + Hydrogen Peroxide in 39 degrees Celsius

 

Step 2: Place each tube to its corresponding temperature

            Tube 1 at room temp.

            Tube 2 at 35 degrees incubator

            Tube 3 at 37 degrees incubator

            Tube 4 at 39 degrees incubator

 

Step 3: After completing step 2, timed the reaction for 30 minutes. After 30 minutes, remove the tubes from the incubator.

 

Step 4: Transfer each tube to each corresponding cuvette and measure the absorbance of hydrogen peroxide at 240 nm. Compute for the concentration of hydrogen peroxide from the absorbance values.

 

Step 5: After computing for each concentration from the absorbance. Tabulate them in a table like the one below

Setup	Absorbance	Hydrogen Peroxide Concentration
Tube 1: Negative control (Catalase enzyme only)
tube 2: Catalase + Hydrogen Peroxide in 35 degrees Celsius
Tube 3: Catalase + Hydrogen Peroxide in 37 degrees Celsius
Tube 4: Catalase + Hydrogen Peroxide in 39 degrees Celsius

 

6. How will you know what the optimum temperature is from your results?

The temperature in the setup with the lowest hydrogen concentration.

The setup with the lowest hydrogen peroxide concentration is the one with the highest catalase activity which means that the temperature in this setup is the optimum temperature.