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Initial procedure due: 4/13B & 4/14A (10 effort points)
Rough draft due: 4/15B & 4/16A (20 effort pts)
Final draft due: 4/21B & 4/22A (50 KS pts)
Lab write-ups are a common part of many science courses and research careers. This writeup will serve as a tool to formally assess (KS: 50 pts) your technical lab skills, as well as your
understanding of the concepts in this particular lab and circulation and digestion unit.
Quick Reference Definitions:
Enzyme:
_____________________________________________________________________________________________
_____________________________________________________________________________________________
Substrate:
_____________________________________________________________________________________________
_____________________________________________________________________________________________
Specificity:
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Introduction -- Enzyme Specificity Lab
How can I figure out if enzymes are specific?
One way to further investigate these molecules is to examine them in a laboratory setting. In this lab, you will be
expected to carry out an inquiry of your own design—that is, you will be asked a question, decide how to test it, and
then analyze the data you collect during your investigation.
Tell me again…what is an enzyme?
Enzymes are biological catalysts. They are globular
proteins that participate in chemical reactions but they
are not consumed by these reactions. They allow a
reaction to proceed more rapidly than it would in the
absence of a catalyst. This is a very important function
in living systems, which operate in a narrow range of
temperature and pH.
Enzymes work to break down other molecules called
substrates. Substrates are molecules to which
enzymes bind or connect.
As you saw with the pepsin computer simulation lab,
variables such as incubation temperature and pH of the
solution can affect the activity, or behavior, of an
enzyme.
Okay, so for this investigation I’m going to work with my lab group to…
Develop a detailed set of tests to provide evidence about the specificity of enzymes. Basically, we want to know if
enzymes work on any type of molecular substrate, or if they are specific to only certain ones?
Your Task:
You will be working with two different enzymes—amylase and lactase. Amylase is an enzyme found in human
saliva. It works to break down starch molecules into individual glucose (simple sugar) monomers. Lactase is an
enzyme that is produced in the small intestine. This enzyme works to break down lactose (the sugar in milk) into
simple sugars. Although we know that amylase works on starch and that lactase works on lactose, we want
to know if these enzymes can work on other substrates as well.
Develop a detailed procedure, including the materials you will need to test the activity and specificity of amylase and
lactase in lab. It is VERY IMPORTANT that you include controls in your tests. Do not even attempt to do the lab
without them! Don’t forget to include this information, along with the independent and dependent variables, in your
hypothesis.
Once you have completed your procedure and it has been approved by your science teacher, you and your lab
group will conduct the experiment that you have designed.
You each will be expected to turn in a formal lab write-up that includes a title, purpose, introduction,
hypothesis, materials, procedure, data and observations, and a conclusion section. The title/purpose and
introduction have been done for you. Don’t forget, you are trying to answer the question: Are enzymes
specific?
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Instructions - Enzyme Specificity Lab
During the Lab:
Every single person expected to keep a lab journal DURING THE LAB AS YOU GO.
Your teacher may collect this for a separate effort grade.
Materials: Everything you touch should be listed on a materials page right away. If you use it, it should be
recorded. Reference the Organic Molecules Lab if needed.
Procedure: Everything you do, step-by-step, in detail should be recorded on procedure pages. This should
be a detailed summary that can be reproduced without error.
Data table: Detailed observations should be made in a table on a data page.
Objective:
Design and perform tests that demonstrate whether enzymes (lactase and amylase) are specific to their
substrates (lactose and starch)
Post-lab:
Rough Drafts should be:
Typed
Spell-checked
Proofread
You are also expected to write in complete sentences in the entire report.
Your write-up should include the following sections outlined in the rubric.
Final Write-ups should be:
Typed
Spell-checked
Proofread
You are also expected to write in complete sentences in the entire report.
Your write-up should include the following sections outlined in the rubric.
Presented in a polished form.
Initial procedure due: 4/13B & 4/14A (10 effort points)
Rough draft due: 4/15B & 4/16A (20 effort pts)
Final draft due: 4/21B & 4/22A (50 KS pts)
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Template – Enzyme Specificity Lab
Title/Purpose:
Investigating Enzyme Specificity
Do enzymes work on any kind of molecular substrate, or are they specific to only one?
Hypothesis:
You will add this
Introduction:
In our last two units in Biology we have studied the importance of organic molecules, what atoms they are made of,
and the characteristics of each. We have also looked at cells and cellular function. We have found that organic
molecules, such as lipids, are important components in the make-up of a cell membrane. We have also learned that
organic molecules like proteins play a crucial role in transporting important food and waste across the membrane of a
cell.
We again look to organic molecules to help us understand the function of special proteins called enzymes. Enzymes
are biological catalysts that participate in chemical reactions, but are not consumed by these reactions. They allow
reactions to proceed more rapidly than they would in the absence of a catalyst. In these reactions, enzymes work to
break down other molecules called substrates. Substrates are molecules to which enzymes bind or connect. The
interaction of enzyme and substrate is a very important function in living systems, which operate in a narrow range of
temperature and pH.
This investigation aims to look at the specificity of an enzyme to its substrate so that we can determine if enzymes
work on only one type of substrate, or on various types.
YOU must add Dependent and Independent Variables, as well
as Controls. (Remember, this is part of your introduction).
Materials and Safety Considerations:
Procedure:
You will add this
Data and Observations:
Results:
You will add this
You will add this
You will add this
Discussion/Conclusion:
You will add this
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Grading Rubric – Enzyme Specificity Lab
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Title and
Purpose
(3pts)
Must be
included,
but is already
written for you.
Hypothesis
(4pts)
Hypothesis is related
to the purpose,
clearly states the
expected outcome,
and is testable.
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The Title/Purpose is
the "big idea" of the
investigation.
It is well thought
out and
encompasses all
of the objectives
of the lab.
Title/Purpose is
written in the form of
a question.
Hypothesis is
relevant to the
purpose, but does
not clearly state the
expected outcome
and/or is not
testable.
Procedure
(X2 up to 8 pts)
(1pt. / test tube)
A Title/Purpose is
written, but it is
vague and does
not fit the "big
idea" of the
investigation.
Title and
Purpose are not
present.
Includes:
Independent
Variable
Dependent
Variable
Control(s)
ALL Variables
and/or Contols are
present but are
incomplete and/or
not properly
identified.
SOME Variables
and/or Controls are
missing
Includes all
materials,
quantities/amounts,
and equipment used
in the experiment,
and includes all
safety
considerations.
Includes some (but
not all) of the
materials,
quantities/amounts,
equipment,
and safety
considerations.
Doesn’t include
most materials,
quantities,
equipment and
safety precautions.
Materials and
Safety
precautions are
not present.
Procedure contains
2-3 mistakes,
inaccuracies, or
omissions.
Procedure contains
4-5 mistakes,
inaccuracies, or
omissions.
Procedure contains
6-7 mistakes,
inaccuracies, or
omissions.
Procedure not
present or steps
are incoherent
or inaccurate.
•
•
Detailed procedure
contains necessary
steps in ordered form
so that another
person could
successfully
reproduce the lab.
Contains 0-1
mistakes,
inaccuracies, or
omissions.
0
Hypothesis is
stated, but is not
relevant to the
purpose and is also
not testable.
•
Materials and
Safety
(3pts)
The Title/Purpose
is the "big idea" of
the lab, but is
missing some of
the lab objectives,
and/or is not written
in the form of a
question.
1
Hypothesis is very
general and/or may
not be testable.
Introduction
(3pts)
For this lab writeup you are ONLY
responsible for
the Independent &
Dependent
Variables, as well
as the Controls
2
Hypothesis is
not present.
Items are
not present.
6
Table includes:
Data and
Observations
(X2 up to 8pts)
• Test Tube label/#
• Enzyme/Substrate
• Reagent used in
test
• Colors observed
• Data in table format
• Table has TITLE
Results
(X2 up to 6pts)
Discussion/
Conclusion
(X3 up to
12pts)
Formatting,
Spelling, &
Grammar
(3pts)
Total (50pts):
• Restates the
hypothesis.
• Supports or
refutes hypothesis
by referring to
data from the lab.
• Shows an in-depth
analysis of data
(explains “why”).
• Describes any
possible
experimental
errors.
• Makes a
connection or
application to the
real-world.
Data/Observations
contains 2-3
mistakes,
inaccuracies, or
omissions.
Data/Observations
contains 4-5
mistakes,
inaccuracies, or
omissions.
Data/Observations
contains 6-7
mistakes,
inaccuracies, or
omissions.
Data/Observations
are described in
detail in sentence
form, but DOES
NOT include an
analysis or
explanation of “why”!
The reader senses
fully what you
observed in the lab.
Data/Observations
are described in
sentence form, but
may have some
missing details.
AND/OR
May include an
analysis or
explanation of
“why”.
Data/Observations
are present but
lack detail and/or
are unclear.
Is missing ONE (or
minor parts) of the
main criteria
AND/OR does not
describe criteria in
detail.
Is missing TWO (or
significant parts) of
the main criteria
AND/OR does not
describe criteria in
detail.
Is missing THREE
OR MORE of the
main criteria
AND/OR does not
describe criteria in
detail.
Has NO formatting,
spelling and/or
grammatical errors.
Has MINOR
formatting, spelling
and/or grammatical
errors.
Has MAJOR
formatting, spelling
and/or grammatical
errors.
Data and/or
observations
are not present
or are
incoherent.
Results are not
present, not
descriptive, or
are incorrect
based on the
data provided.
The Discussion/
Conclusion is
not present,
unrelated, or is
incoherent.
Is incoherent or
unable to be
read and
understood.
Did not check or
proofread
before turning in
final draft.