Final Applied Lab Project (1 credit Lab Component)
Addresses course outcomes 1-4:
recognize and explain how the scientific method is used to solve problems
make observations and discriminate between scientific and pseudoscientific explanations
weigh evidence and make decisions based on strengths and limitations of scientific knowledge and the
use knowledge of biological principles, the scientific method, and appropriate technologies to ask
relevant questions, develop hypotheses, design and conduct experiments, interpret results, and draw
This is the culminating lab assessment in BIOL 103. It is designed to assess your ability to apply the
principles of the scientific method.
The Effect of low pH on Enzyme Activity
Design an experiment in which you will test the effect of an acidic fluid on enzymatic activity. Recall:
enzymes are proteins! To complete this project, it may be useful for you to first review the Scientific
Method Tutorial, the OLI module about pH and enzymes, Lab 1 (Introduction to Science) and Lab 4
(Enzymes). As you review Lab 4, you will be reminded that there are several factors that impact
enzymatic activity: pH, temperature, and amount of reagent. It is OK to use the same
enzyme/substrate/method as you did in lab 4 (but modify the treatment), or you can search on-line to
find a different enzyme/substrate/method for measuring enzyme activity for your project (include all
As you design your experiment for this project, please remember that you are trying to examine how
an acidic fluid will modify the outcome of an enzymatic reaction. To successfully complete this project,
you will need to identify the question(s) being asked in your experiment and the hypothesis that you are
testing. In your experimental design, you must clearly explain what you are doing. That means that you
will need to identify the enzyme, the substrate, the acidic fluid used as treatment, the control treatment
and the method of measuring enzyme activity, as well as explain your experimental protocol. You must
also thoroughly explain how the acidic fluid impacted enzyme activity based on the results from your
own experiment as well as knowledge of enzymes and pH from the OLI modules, lab manual and
potentially additional information sources.
Hint: Keep in mind that the acid will change the environmental conditions of the experiment (for
example, a low pH value could change the shape of the active site on the enzyme protein), without
directly participating in the reaction.
You may need all or some of the following, depending on your experimental design:
Materials from your lab kit:
hydrogen peroxide solution (you can purchase this at a pharmacy if you have used up the bottle that
came with the lab kit)
plastic beakers or cups
yeast (can be purchased at grocery store if more is needed)
marker for labeling of beakers
You may choose to use additional materials (different acidic fluids and/or different organisms and/or
different substrate if you chose an enzyme other than catalase).
Outline (10 points) submit in assignment folder in week 7.
Include the following in your outline:
Name of enzyme you will use
Name of organism (if applicable)
Method for measuring enzyme activity
Treatment: acidic fluid(s), pH, length of exposure, how you will treat your samples
The control(s) in the experiment
How you will present your data (table and/or type of graph)
Anything else you would like to get feedback on before you start your experiment
Write a paper that includes the following:
1. Title page: descriptive title, your name, course name, semester
2. Introduction: general background information about enzymes and specific information about your
chosen enzyme, the question(s) that you are asking and a clear hypothesis for your experiment (15
3. Design an experiment. Provide a detailed description of the materials and methods used to conduct
the experiment. Identify control and experimental samples, as well as independent and dependent
variables. Also include the methods used for data collection and analysis (20 points).
4. Conduct the experiment and record your results. What did you observe? Present your data in table
and/or graph format. Remember to label everything and include the unit of measure with all numbers
5. Use your knowledge of enzymes and pH to interpret and discuss your results. It may be necessary
for you to refer to the OLI course modules, lab manual and/or use additional information resources.
What effect does the acidic treatment have on enzyme activity? Did you get the expected results?
Explain. (15 points)
6. State a specific and accurate conclusion. Is your hypothesis supported by the results? Looking back,
how could you have improved your experiment? (10 points)
7. Include a list of references to all information sources used in APA format (5 points).
It is very important to write with your own words. If you do copy one or two sentences directly (use
sparingly), use quotation marks (") around the copied text, followed by an in-text reference. All
information sources need to be included in the reference list and as in-text references. Plagiarism will be
reported to the proper UMUC authority. Guidance on how to avoid plagiarism can be found here: