3rd Period
Ms. Bortz
Toothpickase Lab
Problem: How does changing enzyme concentration or temperature affect the reaction time of
enzyme activity?
Hypothesis: If enzyme concentration increases, then the rate of enzyme activity will increase
because more enzymes will break down the substrates faster.
Hypothesis: If the temperature decreases, then the rate of enzyme activity will decrease because
enzymes have an optimal temperature under which they function the best.
Materials:
 130 round toothpicks
 Stopwatch or timer


Ice bath
Tape
Procedure:
Part 1: (control group)
1. Count out 50 toothpicks.
2. Spread the toothpicks out in a small area on the lab table.
3. Counter, get the stop watch ready.
4. Complete four timed intervals to determine the rate of activity for toothpickase.
5. When timer says “go” toothpickase will break as many toothpicks completely in half as
possible using one hand, with their eyes closed, breaking one tooth pick at a time, and
leaving all broken pieces in the pile.
6. When timer says “Stop”, toothpickase will stop and the counter will count how many
toothpicks were broken completely in half.
7. The data recorder will record he total number of toothpicks broken in Table 1a.
8. After each round, all toothpicks, broken and unbroken remain for the next round. (If all
tooth picks are broken before the final time interval is finished, record the time at which
the last toothpick was broken.) These rounds represent normal enzyme activity and
concentration, which is the control group.
a. Round 1: 10 second interval
b. Round 2: 20 second interval
c. Round 3: 30 second interval
d. Round 4: 60 second interval
Part 2: (experimental group)
1. Repeat everything from part 1, but this time have toothpickase tape their other hand and
break apart the toothpicks. Keep the toothpicks spread out in a small area, as in Part I.
2. These rounds simulate what happens when enzyme concentration is doubled. Record the
data in Table 2a.
Part 3:
1. Count out 15 toothpicks and place them in a small area on the lab table.
2. Time how long it takes toothpickase to break apart all 15 toothpicks. Record this data in
Table 3. This round will represent the control group.
3. Count out another 15 toothpicks and place them in a small area on the lab table.
3rd Period
Ms. Bortz
4. Have toothpickase place their hand in an ice bath for 30 seconds. When 30 seconds have
passed, toothpickase should immediately break apart all 15 toothpicks. Time how long it
takes and record the data in Table 3. This round will represent the experimental
group.
Table 1a:
Toothpickase Activity
Interval Time (sec.)
10
20
30
60
Cumulative time (sec)
10
30
60
120
Table 1b:
Rate of Toothpickase Activity
Time interval (sec.)
0-10
10-30
30-60
60-120
Table 2a:
Rate of activity (# of toothpicks broken/sec)
.10
.25
.33
.27
Rate of Toothpickase Activity – Doubled Enzyme Concentration
Time interval (sec.)
10
20
30
60
Table 2b:
Total # toothpicks broken
1
5
10
16
Cumulative time (sec)
10
30
60
120
Total # toothpicks broken
4
12
24
42
Rate of Toothpickase Activity – Doubled Enzyme Concentration
Time interval (sec.)
0-10
10-30
30-60
60-120
Table3:
Conditions
Normal Temperature
Reduced temperature
Rate of activity (# of toothpicks broken/sec)
.40
.60
.80
.70
Rate of Toothpickase Activity - Temperature
Toothpick #
15
15
Time (sec)
:85
:143
3rd Period
Ms. Bortz
Toothpicks Broken by Toothpickase at Normal and Lowered Temperature
180
Amount of Time (seconds)
160
140
120
100
80
60
40
20
0
Normal Temperature
Lowered Temperature
Temperature
Ms. Bortz
3rd Period
Qualitative Data:
Graph 1 compares the effect normal concentration versus doubled concentration has on the rate
of enzyme activity. As seen, when the concentration was doubled, the rate of enzyme activity
increased. In both scenarios, the rate peaked and then began to decline, indicating the decline of
substrates for the enzyme to react with.
Graph 2 compares the effect normal temperature versus a lowered temperature has on the rate of
enzyme activity. As shown, enzyme activity greatly decreases with the decrease in temperature,
as indicated by the amount of time it took to break apart 15 toothpicks.
Analysis/Conclusion:
Our hypothesis was supported because by increasing the concentration increased the
enzyme activity rate dramatically. Lowering the temperature dramatically changed the rate of
enzyme reactivity as well. Toothpickase at a normal concentration was able to break sixteen
toothpicks. When the concentration was doubled there was a forty percent increase in enzyme
activity. At room temperature, toothpickase was able to break a total of fifteen toothpicks down
in one minute and twenty five seconds. When toothpickase’s temperature was lowered it took
roughly one minute longer to break down the same number of toothpicks.
During the lab it was possible that some errors occurred. Since there was no set area for
the toothpicks to be placed, it is possible that between experiments we spread the toothpicks out
over differing amounts of space. If we were to repeat this experiment we could place the
toothpicks in a box or draw out a set area on the lab table in which the toothpicks could be
placed.