Handase Lab

 

 

ENZYME RATE OF REACTION FOR CATALASE

 

Introduction:

Chemical reactions make life possible. Hundred of chemical reactions are involved in the process of digesting a candy bar. If these reactions proceeded too slowly, not only would the candy bar remain in the stomach for long time, but the ordinary activities of life would come to a halt as well. Since this is not the case, something in the body must be responsible for speeding up the process. Four things that can speed up chemical reactions are: (1) heat; (2) increasing the concentration of reactants; (3) decreasing the concentration of products; and (4) enzymes, which speed up reaction without themselves being used up.

Enzymes are important in regulating chemical pathways, synthesizing materials needed by cells, releasing energy, and transferring information. Enzymes are involved in digestion, respiration, reproduction, vision, movement, thought, and even in the production of other enzymes. With few exceptions, enzymes are proteins. Simple cells may have as many as 2000 different enzymes, each one catalyzing a different reaction. An enzyme may accelerate a reaction by a factor of 1010 making it happen 10,000,000,000 times faster. Thus, a reaction that might take place as long as 1500 years without an enzyme can be completed in just 5 seconds with an enzyme.

In this lab, your hands are the enzyme Catalase. This enzyme will split H2O2 (a poisonous waste product made by cells) into H20 and O2. You will split the molecule by rippling the paper model down the middle.

Pre Lab Questions:

1. What is an enzyme? What is its functions in living things?

 

2. What are things that can affect the function of an enzyme?

 

3 Write the chemical equation for the breakdown of hydrogen peroxide by the enzyme catalase.

 

4 An enzyme’s efficiency increases with greater substrate concentration, but only up to a point. Why?

 

 

Procedure:

1 Cut out 100 hydrogen peroxide molecules from the paper template.

2. Place 100 paper hydrogen peroxide molecules into a paper bag.

3. One member of your group will do the following:

a) When told to, you will grab one hydrogen peroxide molecule and rip it down the middle. Only rip one hydrogen peroxide molecule at a time.

b) Place the pieces back into the paper bag and grab another hydrogen peroxide molecule.

e) Repeat steps a and b, as fast as you can for 10 seconds. A member of group will be timing you for 10 seconds.

d) Empty your container and count the number of ripped hydrogen peroxide molecules.

e) Record the data in the following table.

 

Time in seconds Ripped Hydrogen Peroxide Molecules Rate of Reaction
0-10 A A
10-30 A A
30-60 A A
60-120 A A
120-180 A A

 

4. Repeat step a – step e for 30, 60, 120, 180 seconds.

5. Graph the results.

6. Determine the rate of reaction for the following times.

The rate of reaction can be calculated by using the following equation:

 

Rate = M2-M1
t2t1

 

a. 0-10 seconds

 

b. 10-30 seconds

 

c. 30-60seconds

 

d. 60-120 seconds

 

e. 120-180 seconds

 

7. Record the above rates in a data table.

8. Graph the results.

Graph Title: ______________________________________________

 

Post Lab Questions:

1. If you were allowed to continue this lab and rip hydrogen peroxide molecules for 240 and 300 seconds. What would happen to the rate of reaction and why will this happen?

 

 

2. What can you say about the length of time and the rate of the reaction?

 

 

3. What would happen to the rate of reaction if you remove the H2O and O2 molecules as soon as they are produced?

 

 

 

Paper Molecules:.