Cellulosic biofuel production in Saccharomyces cerevisiae
Biology 107 Lab Assignment 4: Lab Report for Biofuels lab
• Worth 12% of your grade.
• The page limit is 6 pages. Instructors will stop reading text at the end of the 6th page. This
page limit does not include your full reference section, figures, or appendix.
• Make sure you read the feedback from your earlier assignments and apply it to this one
• As this is the last assignment and you’ve had significant feedback already on parts of a lab
report, instructors will not be providing feedback unless it is requested.
Formatting:
• The assignment must be typed, 12pt font — Arial, Calibri, or Times New Roman, double
spaced with 1” (inch) margins.
• Do not include a separate title page
• Formatting errors can result in deductions
• Your assignment must be uploaded as a PDF. Failure to do this will result in a mark
deduction.
To avoid plagiarism, make sure you review the materials from the Academic Integrity folder and
remember: Cite! Cite! Cite! Your introduction and discussion should be filled with citations! Also
remember: Paraphrase! Paraphrase! Paraphrase! Write everything in your own words! Simply
rearranging words, and swapping out a few words is not paraphrasing. Failure to cite or paraphrase
will result in an Academic Integrity Violation Report. This assignment is individual work. Improper
collaboration is also a violation of the Academic Integrity Policy.
Reminder about extensions: Remember that we have a transparent, universal policy. If you have
used your five extension days, then you will not be successful in getting an additional extension. All
students are very busy with midterms, assignments, and commitments outside of school. Time
management and meeting deadlines are important skills to learn while at University. Don’t wait until
the night before to start your lab report. If you work on your assignment well in advance of the
deadline, you will have no trouble handing it in on time.
Tips:
• Writing is challenging for many students, it will get easier the more you do it (we promise!).
• Written communication is an essential skill for all careers, all students benefit from having more
writing assignments (trust us!).
• If you do not understand the purpose of the experiment, how fermentation works, why you did
the cellulase reaction, etc, it will be very hard to write this lab report. Putting in the time and
effort to understand before you even start writing will have a large pay off.
• Don’t start your lab report the night before it is due. Lab reports take time and it’s a great idea
to leave time for many revisions
• Organize ideas into paragraphs! It is not one mega-paragraph/ section. Each section should
have organized paragraphs.

There are papers posted on Blackboard. Use these to strengthen your introduction and discussion.
Only use the parts of the paper that you understand. Including information that you do not understand
will not make your paper better (in fact, it almost always has the opposite effect!).
Your lab report will contain the following (and be sure to include the headings: Introduction, Results,
Discussion, References, Figures, Appendix):
Introduction
You did not practice writing this section in earlier assignments, but it is important that students in Biol
107 get introduced to how an Intro is written. For this report you will be writing an Intro, but we have
made it worth a lower weighting of this report. Go to the “How to Write an Intro” material to see an
explanation of each of the sections below, as well as examples.
• Relevant background information (be sure the background information is relevant to the
experiment and independent variables)
• Relevance to the “real” world (why should someone care about this?)
• Presentation of research (general overview of what was done)
• Hypotheses (specific prediction supported with scientific rationale)
Results
• Written results for your biofuels lab. Make sure you report the average rate of reaction
using the replicates from your team.
• Compare the results to the controls and incorporate the statistical results from your t-tests
when you write this section. Although it is true that most of you have technical replicates,
for the purpose of practice, we are asking you to use the Student’s t-test to test for
significant differences.
o For example: the rate of CO2 production with sawdust that was not treated with
cellulase, 2mm CO2/min, was not significantly different from the no substrate
control, p= 0.78.
o Another example: The rate of CO2 produced with cellulase treated spinach, 50 mm
CO2/min was similar to the sugar cane control (p= 0.98).
• Be sure to compare the rate of reaction (mm of CO2/min) for the two substrates you tested
to each other, as well as compare cellulase treated to not cellulase treated to identify if the
cellulase treatment increased the rate of reaction (but don’t explain why, as that is what the
discussion is for)
• Do not paste the graphs in this section, figures are attached at the end of the references
section of your report.
Discussion
• Conclusions from your experiment
• In-depth biological mechanism to explain these results.
o This should include (but is not limited to) an in-depth explanation with respect to your
knowledge of fermentation, cellulose, and cellulase. (ex: why was there a higher rate of
reaction in cellulase treated substrates? Why was there a difference in the rates
between the two substrates you tested?). This is the section where you demonstrate in
depth understanding of cellulose, cellulase, and fermentation.
• Use data from the posted to literature to support your results (ex: Smith et al, 2015 also found
that…..)
• Identify limitations to this study. Ex: Are there weaknesses in the experimental design that limit
the conclusions you can draw? Were there weaknesses in the methodology that make it
difficult to compare results/draw conclusions? Was the cellulase reaction done under optimal
conditions (consider the pH and how much time the substrates were in cellulase before
measuring fermentation)? This is not a place to identify mistakes you made (we assume that if
you made human-error type mistakes, you would have re-done the experiment). If you know
you made a technical mistake, you should identify this when you draw conclusions. Are the CI
interval error bars large? What are some reasons that could account for this large variation and
how would they cause it?
• Write one paragraph that compares the substrate supplied by the lab (grass/sawdust/paper) to
whatever you brought in from the perspective of being an ethical, and sustainable substrate for
use in the biofuels industry. Make sure this is supported (and cited) with literature.
• Future Work: You did not write this in your Enzymes Discussion, but write a short paragraph
that proposes future work. Propose the next experiment you should do to address the
limitations or add on to the knowledge gained from your biofuels experiment. Provide a
rationale for the future work. Clearly communicate why this future work is important and how it
will generate new knowledge that contributes to this field of research.
References
• Make sure the reference list is alphabetical and follows the format outlined in the guidelines
• Make sure in text citations are provided in places they are necessary and follow the correct
format. When in doubt, cite.
Figures
• Figure 1. Graph (with Figure legend) for the results from the fermentation experiment. For
this Figure, please graph the rate of reaction (mm of CO2/min), where the data is the average
of your replicates with CI error bars. If you do not know how to calculate the rate of
fermentation from your data, be sure to discuss with your instructor. (To be clear, this is not
the graph with mm of CO2 on the Y-axis, and time on the X-axis. You need to make this graph
in order to calculate the rates but do not include it with your lab report. Once you have the
rates from each replicate, then you can use the means to create a bar graph with substrate
on the X-axis and rate (mm of CO2/ min) on the Y.
Appendix
Your Appendix must include the following:
• Descriptive stats table (mean and CI)
• Table with p-values from your t-tests
• Show your calculations for how you determined the rate of reaction. Remember to avoid data
points where CO2 is not being produced (ex: lag, stationary phase) when calculating the rates
Additional Attachments
Please remember to upload your excel workbook as an additional file so your instructor can access your
data if needed.