TCCRI College Readiness Assignments
Instructor Task Information
Enzymes in Action
Overview
Description
In this activity, students are asked to collect background information regarding the
structure and functioning of enzymes. The students will then explore enzymes in the
laboratory setting. The activity also allows students the opportunity to design and
conduct a lab to measure the impact of a single variable such as temperature, pH,
and substrate concentration on enzyme activity.
Final Product: After completing the investigation, students will prepare a written
report of the lab results.
Course
Biology
Task Level
Grade 10–12
Cross-Disciplinary Standards Assessed
I.
Key Cognitive Skills
A.1. Engage in scholarly inquiry and dialogue.
B.2. Construct well-reasoned arguments to explain phenomena, validate
conjectures, or support positions.
B.3. Gather evidence to support arguments, findings, or lines of reasoning.
B.4. Support or modify claims based on the result of inquiry.
C.1. Analyze a situation to identify a problem to be solved.
C.3. Collect evidence and data systematically and directly relate to solving a
problem.
D.1. Self-monitor learning needs and seek assistance when needed.
D.2. Use study habits necessary to manage academic pursuits and requirements.
D.3. Strive for accuracy and precision.
D.4. Persevere to complete and master tasks.
E.1. Work independently.
E.2. Work collaboratively.
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Enzymes in Action
Instructor Task Information
F.1. Attribute ideas and information to source materials and people.
F.2. Evaluate sources for quality of content, validity, credibility, and relevance.
II. Foundational Skills
B.1. Write clearly and coherently using standard writing conventions.
B.3. Compose and revise drafts.
C.4. Evaluate the validity and reliability of sources.
E.1. Use technology to gather information.
Science Standards Assessed
I.
Nature of Science: Scientific Ways of Learning and Thinking
A.2. Use creativity and insight to recognize and describe patterns in natural
phenomena.
B.1. Design and conduct scientific investigations in which hypotheses are
formulated and tested.
C.3. Demonstrate skill in the safe use of a wide variety of apparatuses,
equipment, techniques, and procedures.
D.1. Demonstrate literacy in computer use.
D.3. Demonstrate appropriate use of a wide variety of apparatuses, equipment,
techniques, and procedures for collecting quantitative and qualitative data.
E.2. Use essential vocabulary of the discipline being studied.
III. Foundation Skills: Scientific Applications of Communication
A.1. Use correct applications of writing practices in scientific communication.
B.2. Set up apparatuses, carry out procedures, and collect specified data from a
given set of appropriate instructions.
C.1. Prepare and present scientific/technical information in appropriate formats
for various audiences.
D.1. Use search engines, databases, and other digital electronic tools effectively
to locate information.
VI. Biology
B.2. Describe the structure and function of enzymes.
Objectives
Students will:
•
Describe an enzyme in terms of its function in chemical reactions and
substrate/product relationships.
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Enzymes in Action
Instructor Task Information
•
Define and recognize examples of the following terms related to
enzymes: catalysts, active site, substrate, product, induced fit, competitive
inhibition, noncompetitive inhibition, activation energy, and feedback inhibition.
•
Design and conduct investigations to measure the effect on initial
reaction rates produced by changes in temperature, pH, enzyme concentration,
or substrate concentration.
•
Communicate the results of an investigation measuring the effect of a
manipulated variable such as temperature, pH, enzyme concentration, or
substrate concentration.
Preparation
•
Read the Instructor Task Information and the Student Notes.
•
Prepare student copies of the Student Notes pages, Introduction to
Enzymes WebQuest, Introduction to Enzyme Action, and Lab Report Grading
Rubric handouts.
•
Identify key words that students can use to conduct their Internet search.
You may want to list several Web site addresses to help direct students as they
conduct their Internet research.
•
Secure computer access necessary for web search.
•
Gather lab equipment and supplies needed for both the preliminary
investigation and the student inquiry investigation.
•
Provide students with copies of the preliminary investigation protocol.
Prior Knowledge
In order to be successful in these activities students need to be able to:
•
Safely handle chemicals in the laboratory.
•
Understand the structural composition of a protein.
•
Recognize biological macromolecules.
•
Design a data table for collection of experimental data.
•
Prepare a graphical representation of data collected.
Vocabulary
•
Activation energy
•
Active site
•
Catalyst
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•
Competitive inhibition
•
Enzymes
•
Enzyme-catalyzed reaction
•
Feedback inhibition
•
Induced fit
•
Noncompetitive inhibition
•
pH
•
Product
•
Substrate
Time Frame
This assignment will require approximately 12 days to complete. Eight of the days will
require time during the instructional period. Students are expected to prepare their
lab reports outside of class. If class time is limited, students can also conduct their
web search outside of class.
Day 1: Introduce enzymes. Begin enzyme web search.
Day 2: Continue enzyme web search.
Day 3: Web search due at end of class.
Day 4: Conduct preliminary enzyme lab.
Day 5: Design Enzyme Inquiry Lab.
Day 6: Finalize design. Peer review design.
Day 7: Conduct Enzyme Inquiry Lab.
Day 8: In class, explain the lab report expectations.
Day 9–12: Outside of class time, students will prepare lab report. Report due at the
end of class on day 12.
The Introduction to Enzyme Action lab could be done as early as day one in this
sequence.
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Instructor Task Information
Instructional Plan
Getting Started
CCRS Performance Expectations
Cross-Disciplinary Standards:
I.
Key Cognitive Skills
A.1. Engage in scholarly inquiry and dialogue.
B.3. Gather evidence to support arguments, findings, or lines of reasoning.
C.1. Analyze a situation to identify a problem to be solved.
C.3. Collect evidence and data systematically and directly relate to solving a
problem.
D.1. Self-monitor learning needs and seek assistance when needed.
D.2. Use study habits necessary to manage academic pursuits and
requirements.
D.3. Strive for accuracy and precision.
D.4. Persevere to complete and master tasks.
E.1. Work independently.
F.1. Attribute ideas and information to source materials and people.
F.2. Evaluate sources for quality of content, validity, credibility, and
relevance.
II. Foundational Skills
C.4. Evaluate the validity and reliability of sources.
E.1. Use technology to gather information.
Science Standards:
I.
Nature of Science: Scientific Ways of Learning and Thinking
D.1. Demonstrate literacy in computer use.
E.2. Use essential vocabulary of the discipline being studied.
III. Foundation Skills: Scientific Applications of Communication
A.1. Use correct applications of writing practices in scientific communication.
D.1. Use search engines, databases, and other digital electronic tools
effectively to locate information.
VI. Biology
B.2. Describe the structure and function of enzymes.
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Enzymes in Action
Instructor Task Information
Learning Objectives
Students will:
•
Describe an enzyme in terms of its function in chemical reactions and
substrate/product relationships.
•
Define and recognize examples of the following terms related to
enzymes: catalysts, active site, substrate, product, induced fit, competitive
inhibition, noncompetitive inhibition, activation energy, and feedback
inhibition.
Procedure
1. Use an enzyme model, video clip, or instructor-made presentation to teach
the components of an enzyme-catalyzed reaction, including the enzyme,
substrate, enzyme/substrate complex, product, reactant, and induced fit.
2. Have students practice explaining the catalytic cycle using the think-pairshare strategy or similar active student engagement strategy as they answer
the following questions:
a. What is the relationship between an enzyme and a substrate molecule?
b. Would a substrate be a product or reactant in an enzyme-catalyzed
reaction?
c.
Describe induced fit.
d. How are competitive inhibition and non-competitive inhibition similar?
How are they different?
e. Draw an enzyme/substrate complex formed during the reaction in which
catalase catalyzes the decomposition of hydrogen peroxide into water
and oxygen.
3. Lead students in a web search to expand their understanding of enzymes,
activation energy, and forms of inhibition. See the Introduction to Enzymes
WebQuest handout. If possible, the handout should be provided in an
electronic version for student access. The following terms will help students
narrow the search:
a. Question 1 – macromolecule enzyme
b. Question 2 – enzymes found in human body
c.
Question 3 – enzyme specificity definition
d. Question 4 – activation energy
e. Question 5 – factors affecting enzyme activity
f.
Question 6 – enzyme inhibition
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Instructor Task Information
4. Class discussion may be needed to address the issues of Web site reliability,
plagiarism, and the need to cite references on the answer document.
Investigating
CCRS Performance Expectations
Cross-Disciplinary Standards:
I.
Key Cognitive Skills
B.3. Gather evidence to support arguments, findings, or lines of reasoning.
B.4. Support or modify claims based on the result of inquiry.
C.1. Analyze a situation to identify a problem to be solved.
C.3. Collect evidence and data systematically and directly relate to solving a
problem.
D.1. Self-monitor learning needs and seek assistance when needed.
D.2. Use study habits necessary to manage academic pursuits and
requirements.
D.3. Strive for accuracy and precision.
D.4. Persevere to complete and master tasks.
E.1. Work independently.
II. Foundational Skills
B.1. Write clearly and coherently using standard writing conventions.
B.3. Compose and revise drafts.
Science Standards:
I.
Nature of Science: Scientific Ways of Learning and Thinking
A.2. Use creativity and insight to recognize and describe patterns in natural
phenomena.
B.1. Design and conduct scientific investigations in which hypotheses are
formulated and tested.
C.3. Demonstrate skill in the safe use of a wide variety of apparatuses,
equipment, techniques, and procedures.
D.3. Demonstrate appropriate use of a wide variety of apparatuses,
equipment, techniques, and procedures for collecting quantitative and
qualitative data.
III. Foundation Skills: Scientific Applications of Communication
B.2. Set up apparatuses, carry out procedures, and collect specified data
from a given set of appropriate instructions.
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Enzymes in Action
Instructor Task Information
VI. Biology
B.2. Describe the structure and function of enzymes.
Learning Objectives
Students will:
•
Design and conduct investigations to measure the effect on initial
reaction rates produced by changes in temperature, pH, enzyme
concentration, or substrate concentration.
Procedure
1. Students will begin by conducting a guided inquiry investigation of enzyme
activity to gain the experience needed to design an experiment on factors
affecting the rate of enzyme activity. See the protocol as described in the
Introduction to Enzyme Action handout.
2. In the post-lab class discussion and lab questions, students should express
understanding of the functioning of a typical enzymatic pathway.
3. Lead a discussion in which students predict the impact of a change in pH,
temperature, or concentration on the activity of an enzyme.
4. Allow students time to work in small groups to formalize predictions, write a
hypothesis, and design an experiment to test the hypothesis.
5. The following day, students should exchange their experimental designs that
include the experimental protocol and conduct a peer review of the design.
Discuss with students the components they should check for as they perform
the peer review.
6. Students should edit their reviewed protocols and then conduct the
investigation.
Drawing Conclusions
CCRS Performance Expectations
Cross-Disciplinary Standards:
I.
Key Cognitive Skills
B.2. Construct well-reasoned arguments to explain phenomena, validate
conjectures, or support positions.
B.4. Support or modify claims based on the result of inquiry.
D.1. Self-monitor learning needs and seek assistance when needed.
D.2. Use study habits necessary to manage academic pursuits and
requirements.
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Enzymes in Action
Instructor Task Information
D.3. Strive for accuracy and precision.
D.4. Persevere to complete and master tasks.
E.1. Work independently.
F.1. Attribute ideas and information to source materials and people.
II. Foundational Skills
B.1. Write clearly and coherently using standard writing conventions.
B.3. Compose and revise drafts.
Science Standards:
I.
Nature of Science: Scientific Ways of Learning and Thinking
A.2. Use creativity and insight to recognize and describe patterns in natural
phenomena.
E.2. Use essential vocabulary of the discipline being studied.
III. Foundation Skills: Scientific Applications of Communication
A.1. Use correct applications of writing practices in scientific communication.
C.1. Prepare and present scientific/technical information in appropriate
formats for various audiences.
VI. Biology
B.2. Describe the structure and function of enzymes.
Learning Objectives
Students will:
•
Communicate the results of an investigation measuring the effect of a
manipulated variable such as temperature, pH, enzyme concentration, or
substrate concentration.
Procedure
1. Describe the attributes of the components expected to be found in a formal
lab report.
2. Review the lab report grading rubric with students to ensure that all students
understand the report expectations.
3. Devote 3–5 minutes at the beginning or ending of the class period over the
next several days to answer student questions regarding the preparation of
the lab report.
4. Remind students as the lab report due date approaches.
5. (Optional) Set aside class time to have student conduct a peer review of a
rough draft of the lab report.
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Instructor Task Information
Scaffolding/Instructional Support
The goal of scaffolding is to remove support gradually to encourage student success,
independence, and self-management. The following suggestions are examples of
scaffolding that can be used by instructors to meet diverse student needs while students
are completing this assignment:
•
Some students will benefit from being provided a list of questions that
should be answered in the body of a well-written conclusion section such as:
•
What general data trends were found?
•
Is your hypothesis supported or not supported?
•
What were possible sources of errors?
•
What changes would you now make to the protocol?
•
What additional questions have been generated by your results?
•
The rigor of the experimental design would be raised by expecting
students to test additional variables. A second way to increase the rigor would be
to add an additional enzyme. For example, the impact of increased temperature
could be measured using the enzyme catalase and then, in a second phase of
the lab, using the enzyme lactase.
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Instructor Task Information
Solutions
The solutions provided in this section are intended to clarify the problem for instructors.
These solutions may not represent all possible strategies for approaching the problem or
all possible solutions. It should be used for reference only.
Students should use reliable Web sites as sources when completing the Introduction to
Enzymes WebQuest handout.
Students should design a controlled experiment to test a single variable. Make sure
students identify their control group.
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Instructor Task Information
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TCCRI College Readiness Assignments
Student Notes
Enzymes in Action
Introduction
Enzymes are proteins that catalyze a myriad of chemical reactions in living
organisms. Enzymes are key players in the process of chemically breaking down
food in the digestive system. Enzymes also regulate processes such as DNA
replication, cellular respiration, and photosynthesis. An understanding of
enzymes is vital to understanding the complex chemical pathways that occur
within living cells.
In this activity, you will explore the fundamental concepts associated with
enzymes and enzymatic regulation. In addition, you will explore the chemical
reactivity of enzymes such as catalase. You will also have the opportunity to
design an investigation to explore the impact of pH, temperature, or
concentration on enzyme activity. The results of your investigation, as well as
your investigational design, will be communicated through a formal lab report.
Directions
Getting Started
1. Listen to your instructorʼs introduction to enzyme-catalyzed reaction.
Participate in a think-pair-share discussion in which you answer the provided
questions.
2. Access the Internet as instructed by your instructor.
3. Complete the Internet-based search activity handout, Introduction to
Enzymes WebQuest.
4. Submit the completed handout.
Investigating
1. Conduct the initial observational lab activity, Introduction to Enzyme Action.
2. Answer the questions on the handout and write the summary paragraph.
3. Submit your completed handout and summary paragraph.
4. After a discussion within your lab group, select one of the following variables
to further investigate: pH, temperature, substrate concentration, or enzyme
concentration.
5. Review the Lab Report Grading Rubric handout, and work with your lab
partners to design a controlled experiment to test the selected variable.
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Enzymes and Their Function
Student Notes
6. Exchange your experimental design with another group for review.
7. Edit your design based on the peer review, and conduct the controlled
experiment, collecting all necessary data.
Drawing Conclusions
1. Prepare a formal lab report detailing your experiment.
2. Submit your lab report.
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TCCRI College Readiness Assignments
Student Handouts
Introduction to Enzymes WebQuest
Use your Internet research skills to find valid answers to each of the following questions
or tasks. Cite the sources of each answer in the space provided by each item.
1. Describe the biochemical composition of an enzyme and identify the
macromolecule group for enzymes.
Citation:
2. Identify 5 enzymes in the human body and list the substrate(s), product(s) of the
reaction catalyzed by each enzyme, and the typical location of the enzyme in the
human body.
Enzyme
1.
Substrate(s)
Product(s)
Location in Body
2.
3
4.
5.
Citation:
3. Explain what is meant by the phrase “enzyme specificity.”
Citation:
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Enzymes in Action
Student Handouts
4. Describe activation energy and explain how it is impacted by an enzyme. Draw a
graph to support your explanation.
Citation:
5. Identify 3 factors that can influence the rate of an enzyme-catalyzed reaction.
Describe how each factor affects the rate.
Citation:
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Enzymes in Action
Student Handouts
6. Describe and give a specific enzyme-related example of each of the following
terms.
a. Feedback inhibition:
Example:
Citation:
b. Competitive inhibition:
Example:
Citation:
c. Non-competitive inhibition:
Example:
Citation:
d. Allosteric regulation:
Example:
Citation:
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Enzymes in Action
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Student Handouts
SH-4
Enzymes in Action
Student Handouts
Introduction to Enzyme Action
Enzymes catalyze a wide variety of reactions in living organisms. These proteins serve
as catalysts lowering the energy of activation for a particular reaction. Enzymes have an
active site with a structural arrangement that allows only specific substrate molecules to
attach. As a result, enzymes exhibit specificity to a particular substrate or reactant in a
chemical reaction. For example, the enzyme lactase is specific to the substrate molecule
lactose, helping break it into the products glucose and galactose. Similarly, the enzyme
sucrase is specific to the substrate sucrose.
In this activity, you will identify the specific substrate molecule for the enzyme catalase.
The presence or absence of enzyme activity will be determined by observing the
appearance of product molecules.
Materials:
•
4 test tubes
•
Test tube rack
•
1 mL syringe
•
10 mL syringe
•
10 mL distilled water
•
10 mL ethanol
•
10 mL 95% acetic acid (vinegar)
•
10 mL hydrogen peroxide
•
10 mL 5% sodium chloride solution
Procedure:
1. Discuss with your lab group which of the four chemicals provided will serve as a
substrate for the enzyme catalase and then formulate and record your hypothesis
below.
Hypothesis:
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
2. Obtain four clean test tubes and place 10 mL of each of the four test chemicals
into four separate test tubes. Be sure to thoroughly rinse the syringe as you move
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Enzymes in Action
Student Handouts
from one chemical to the next.
3. Add 1 mL of catalase solution to the test tube containing ethanol. Observe the
reaction and record your observations.
4. Repeat step 3 using acetic acid, hydrogen peroxide, and sodium chloride
solutions.
5. Repeat steps 3 and 4 using distilled water instead of the catalase solution.
6. Record your observations and answer the questions below:
Data:
Observations
Chemical
Catalase Added
Distilled Water
Added
Ethanol
Acetic Acid
Hydrogen Peroxide
Sodium Chloride
Discussion Questions:
1. Which chemical produced the most obvious reaction when catalase was added?
2. Was your hypothesis supported by the observations? Explain.
3. On a separate sheet of paper, prepare a paragraph summarizing your results and
understanding of enzyme activity. Use the following terms in your summary
statement: substrate, product, reactant, activation energy, and catalyst.
Additionally, identify the enzymes, substrate, and products of the reaction
observed in this activity.
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Enzymes in Action
Student Handouts
Lab Report Grading Rubric
REPORT ITEM
Title
POSSIBLE
POINTS
3
Introduction
Background information
Purpose of the experiment
Hypothesis
(12)
4
4
4
Materials and Procedures
Materials listed
Procedures stated
Control(s) identified
(15)
5
5
5
Results/Data Collection/Analysis
Data recorded in tables
Graph(s) present
Titled
Axes labeled
Variables correctly identified
(20)
8
6
2
2
2
Conclusion
Results aummarized
Errors identified
Conclusion stated
Improvements recommended
(16)
4
4
4
4
Literature Citation
Cited within write up
Citation information correct
(4)
2
2
Questions
Questions written
Correctness
(30)
10
20
EARNED
POINTS/comments
Comments
TOTAL POINTS
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(100)
SH-7