The goal of this project is for students to evaluate the effect of an acid on enzymatic activity. As part of this assignment, students must identify the source of enzyme and the acid used. While working though this project, students must also make sure that the following questions/points are addressed:
- Introduction – Discuss what enzymes are. Discuss what pH is. How are they related? Which enzyme is being studied in this experiment and what does it do? Include products and reactants. What questions are you asking about enzymes and pH? (1 – 2 paragraphs)
- Clearly state the hypothesis. (1 sentence)
- Design an experiment. Be sure to include a comparison of at least 2 solutions with a different pH. Provide a detailed account of the materials and methods used to conduct the experiment. Include controls and variables (independent, dependent, controlled). Also include the methods for data collection and analysis. (list materials used, numbered list of methods used)
- Results – Conduct the experiment and record your results. What was observed? Which samples showed bubbling? (provide tables, graphs and pictures). Remember to label everything and include unit of measure with all numbers.
- Discussion – Use knowledge about enzymes and pH to interpret and discuss results. It may be necessary to refer to the OLI course modules, lab manual and/or additional resources. What effect does the acidic treatment have on the enzyme activity? Looking back, how could this experiment have been improved ? (1 – 2 paragraphs)
- Conclusion – State a specific and accurate conclusion. Was your hypothesis supported by the results? (1 – 2 paragraphs)
- Include a list of references to all information sources used in APA format.
Demonstration of your knowledge of basic laboratory skills, experimental design, and/or data evaluation will be assessed by the submission of an applied final lab project.
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 scientific method
- 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 conclusions
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 references).
As you design your experiment for this project, please remember that you are trying to examine how anacidic fluidwill 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.
You may need all or some of the following, depending on your experimental design:
Materials from your lab kit:
- pH paper
- 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)
- plastic bottle
- 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).
*Materials used that are not part of the lab kit nor are commonly found in someone’s kitchen must include a note stating how the item was obtained and from where.