Download Enzyme Modeling Lab

Enzyme Modeling Lab
Lab Directions and Rubric
This lab activity, revised from the Access Excellence1, will help you model how enzymes
interact with their substrates under different environmental conditions.
Overview:
Compare the action of an enzyme on a substrate in normal vs. denatured conditions. Recall that
denaturation occurs when the three dimensional shape of a protein is lost due to some external
factor.
You will not be submitting a formal lab report, but rather a table, graph and answers to thoughtprovoking discussion questions. The rubric for grading is below.
Materials:
● a partner (a friend, sibling, or parent)
● 50 pennies placed tails side up for each trial
● stop watch
● masking tape
Procedure:
Trial I: Normal conditions
Use fifty pennies placed tails-side up. Have your partner time you for ten seconds as you try to
turn as many as you can from tails-side up to heads-side up. At the end of the first ten-second
time period, record the number of pennies you turned in the Data Table and then DO NOT put
them back in the pile of 50. You will continue turning the remaining pennies in ten second
intervals. Each time, make sure to record your results in the table and DO NOT return the
pennies to the pile. You are finished when you have turned all 50 pennies from tails-side up to
heads-side up.
Trial II: Abnormal conditions
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Reset all of the pennies by turning all of them tails side up. Use the tape to bind the four fingers
on your turning hand together. This represents partial denaturation of the enzyme. Repeat the
procedure from Trial I by turning the pennies one by one in ten second intervals. You may need
to add more ten-second periods if you still have pennies to turn. Make sure you record your
data in the Trial II column of your data table after each 10 second period.
Results:
Record your data in a table similar to the one below.
Time Periods (seconds)
Trial I (# of pennies)
Trial 2 (# of pennies)
0-10
10-20
20-30
30-40
40-50
50-60
60-70
70-80
Make a line graph (preferably showing two lines) that displays the number of pennies turned
over per time period for both trials.
● Use a graphing program on your computer or one of the free online resources provided
in the sidebar.
● Follow the guidelines in the Scientific Method module for constructing graphs.
● Use a different color for each trial (line) on the graph.
Discussion Questions:
Answer each in complete sentence(s).
1.What was the enzyme in this activity?
2.What was the substrate?
3.What would be an appropriate name for this enzyme?
4.In Trial I, what happens to the reaction rate (amount of product over time) as the supply of
substrate runs out? Why?
5.Describe the difference between the graphs of reaction rates for Trial I and II. Explain why
this is so.
6.Name at least one factor that could have caused the denaturation in Trial II (with real
enzymes)?
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7.This lab was supposed to model the action of an enzyme. Describe some sources of error
in this lab.
Submit your lab as one document if possible.
Grading:
The following criteria will be used to evaluate your lab:
Criteria
Points Possible
Results
Data Table (10)
● Properly set up per example
● Data included for both trials
Graph (20)
● Digitally produced (not hand-drawn)
● Proper title
● Line graph(s) for both trials constructed (preferably) on same graph
● Axes placed properly and labeled with units
● Trial I/II colored or labeled clearly
30
Discussion Questions
● 10 points per question
● Answered in complete sentences
70
TOTAL
100
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