Download Enzyme Lab

Enzyme Reaction Rate Using the Enzyme “Toothpickase”
Background Information:
Enzymes are agents that change the rate of reaction without being changed themselves. The active site
on an enzyme is open to a substrate and will change it by carrying out the reaction. Competitive
inhibitors sometimes get in the way by either blocking or changing the shape of the active site on an
enzyme. Concentration of the enzyme and the substrate are important and will impact the rate of
reaction as well. But what else might impact the rate of reaction?
In this activity, you are the enzyme “Toothpickase.” The active sites are your hands and your function is
to break any non-colored toothpick (the substrate) in half. Your goal is to break all non-colored
toothpicks quickly and efficiently without hurting yourself in the process (because enzymes are reusable
and a hurt or damaged enzyme no longer functions properly). You are not to break any colored
toothpicks, as your actives sites aren’t built for them.
Pre-Lab Questions:
1.
Where is your active site?
2. What is the product of toothpickase with its substrate?
3. What exactly is the substrate that toothpickase can interact with?
4. What factors might impact the ability of toothpickase to affect its substrate?
5. Write a hypothesis for this experiment.
Materials
o
o
o
o
100 non-colored toothpicks
50 colored toothpicks
Beaker filled halfway with water and ice
Stop watch
Lab Procedure
1. Between you and your partner, pick a person to be the recorder and a person to be the enzyme.
The recorder will work the stop watch and record observations while the enzyme will perform
the rest of the lab.
2. Mix your toothpicks up so that you have one big pile of colored and non-colored toothpicks
together.
3. Separate your toothpicks into 5 piles containing 30 toothpicks in each pile. Arrange piles in front
of the enzyme in a semi-circle.
4. You and your partner will now begin metabolizing the substrate by breaking toothpicks, one at a
time. Using the chart below, perform 5 timed trials and record the number of toothpicks
metabolized per timed interval.
Time (in seconds)
5
10
20
30
30
Special Instructions
None
None
Cross fingers while performing
trial
Dip hands in water for 30 sec.
before performing trial
None
Toothpicks Metabolized
5. Construct a line graph using data you collected.
6. For each interval of time, calculate the rate of reaction using the following formula:
M2 – M1
T2 – T1
M = number of toothpicks metabolized
T = time
7. Record your data in the table below.
Time Interval (in seconds)
Rate of Reaction on Toothpickase
(in toothpicks
metabolized/seconds)
Special Notes
5 seconds
10 seconds
20 seconds
30 seconds
30 seconds
Post Lab Questions
1.
Did temperature affect toothpickase’s ability to metabolize the substrate?
2. Did changes to the active site of the enzyme affect toothpickase’s ability to metabolize the
substrate?
3.
Did the substrate concentration play a role in toothpickase’s ability to metabolize effectively?
4.
Do you think heat would increase or decrease toothpickase’s activity on the substrate?
5. Write a conclusion for this lab.