enzymes post lab 1 2

Reminder: All post labs need to be 1- typed (not handwritten) , 2- original (not copied from a classmate), 3- answered using complete statements and 4- turned in at the beginning of the lab.
Post-lab questions for Topic 5 – Enzymes
Name: Date: Group: T W R
Formation and Detection of Benzoquinone
Table 1. Formation and Detection of Benzoquinone: Record Absorbance
Time
2A-Potato extract + cathecol
2B- Potato extract + water
2C- Catechol + water
After 10 min

1- What were the substrate, enzyme and product of the enzymatic reaction?
2- What is the purpose of tubes 2B and 2C?
Enzyme Specificity
Table 2 – Specificity of Cathecol oxidase for different substrates
Prediction: ____________________________________________________________________________ Absorbance 540nm
Time
Tube 3A; Cathecol
Tube 3B: Hydroquinone
Tube 3C: dH2O
After 10 min

3- Based on your knowledge of the structures of the two substrates ( p 107) what apparently determines the specificity of cathecol oxidase?
4- Conclusion (was your prediction correct?)
Effect of temperature on Enzyme Activity
Prediction: ___________________________________________________________________________
Table 3. Effect of temperature on enzyme activity Absorbance 540nm
Time
Tube 4A
Tube 4B
Tube 4C
Tube 4D
Tube 4E
Tube 4F
After 10 min 5- Construct a graph using Excel for the temperature data and indicate the optimal temperature for this reaction to occur.

6- If the tube incubated at 100 C was placed back in the optimum temperature, would a reaction occur? Explain.
7- What can you conclude from the graph?
Effect of pH on Enzyme activity
Prediction:_________________________________________________________________________
Table 4. Effect of pH on enzyme activity