Catalase (the enzyme) is found in the cells of the liver where it breaks down hydrogen peroxide (the substrate) into water and oxygen according to this equation.
PURPOSE: To study enzymes and conditions affecting their activity.
MATERIALS AND METHODS: Wear safety glasses!
NEXT: As you perform the tests below, consider how the reactions compare in all tubes and rank them in the table.
(with hydrogen peroxide)
|1. liver (crushed)|
|2. liver (not crushed)|
|3. liver (crushed and ice)|
|4. liver (crushed and acid)|
|5. manganese dioxide|
QUESTIONS: Answer in full sentences on separate paper.
|1.||What was the purpose of test tube 6?|
|2.||Compare your results for test tube 1 and 2. Try to explain the difference.|
|3.||Which substance is the inorganic catalyst in the experiment and why was it helpful to see it's reaction in the context of this lab?|
|4.||a)||What was the purpose of the glowing splint test?|
|b)||Which tubes performed best and why?|
|5.||a)||What was the effect of cooling down the enzyme with ice?|
|b)||What temperature do enzymes normally operate at in the body?|
|c)||If catalase enzyme was placed in a test tube and heated to 100OC, what results would you expect from a glowing splint test? Why?|
|6.||a)||What was the effect of adding acid to the enzyme?|
|b)||How would you expect the enzyme pepsin to perform in this part of the experiment? Why?|