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Cellular Respiration and Photosynthesis Lab Project

Your task is to design a lab that investigates a question regarding either cellular respiration or photosynthesis. Although there is a great deal of creativity that may be employed, your lab must address a meaningful question and answer that question using good scientific methodology.

Possible questions include:: Would other substrates be as effective as glucose in alcoholic fermentation?; Would fermentation rates change with different types of yeasts?; What environmental conditions are optimum for alcoholic fermentation?; What temperature ranges?; What pH ranges?; What is the maximum amount of ethyl alcohol that can be tolerated by yeast cells?; Sodium fluoride, commonly used to prevent tooth decay, inhibits an enzyme in glycolysis. At what concentration is it most effective?; Would adding MgSO₄ enhance glycolysis? MgSO₄ provides Mg⁺⁺, a cofactor necessary to activate some enzymes in glycolysis.; Would other substrates be as effective as glucose in cellular respiration?; What environmental conditions are optimum for cellular respiration?; What temperature ranges?; What pH ranges?; What inhibitors of cellular respiration are most effective? Consider the following: Rotenone, an insecticide, inhibits electron flow in the electron transport chain; Oligomycin, an antibiotic, inhibits ATP synthesis; Malonate blocks the conversion of succinate to malate. How would you determine if this is competitive or noncompetitive inhibition?; Antimycin A is an antibiotic that inhibits the transfer of electrons to oxygen.; What is the effect of different wavelengths of light on the rate of photosynthesis in Elodea?
What is the effect of different temperatures on the rate of photosynthesis in Elodea?: What is the absorption spectrum of marine algae that occur at difference depths?

Procedure

1. Decide on one or more questions to investigate.

2. Formulate a testable hypothesis.

3. Summarize the experiment.

4. Predict the results of your experiment based on your hypothesis.

5. Outline the procedures used in the experiment

a. List each step in your procedure in numerical order.

b. Remember to include the number of repetitions (usually a minimum of five), levels of treatment, appropriate time intervals, and controls for each procedure.

c. If you have an idea for an experiment that requires materials other than those provided, ask about their availability. If possible, additional supplies will be made available.

d. When carrying out an experiment, remember to quantify your measurements when possible.

6. Perform the experiment, making observations and collecting data for analysis.

7. Record observations and data.

a. Design tables and graphs, at least one of each. Be thorough when collecting data. Do not just write down numbers, but record what they mean as well. Do not rely on your memory for information that you will need when reporting your results.

8. Prepare your discussion. Discuss your results in light of your hypothesis.

a. Review your hypothesis. Review your results (tables and graphs). Do your results support or falsify your hypothesis? Explain your answer, using your data for support.

b. Review your prediction. Did your results correspond to the prediction you made? If not, explain how your results are different from your prediction, and why this might have occurred.

c. If you had problems with the procedure or questionable results, explain how they might have influenced your conclusion.

d. If you had an opportunity to repeat and expand this experiment to make your results more convincing, what would you do?

e. Summarize the conclusion you have drawn from your results.

8. Be prepared to report your results to the class. Prepare to persuade your fellow scientists that your experimental design is sound and that your results support your conclusion.

9. Prepare a final report.

a. Your report must include an introduction, materials and methods, results, discussion and literature cited.

b. Keep in mind that although you have performed the experiments as a team, you must turn in a lab report of your original writing. Your tables and figures may be similar to those of your team members, but your Results and Discussion sections must be the product of your own literature search and creative thinking.

10. The report will be due January 20, 2003.

Links

Thin layer chromatography

Isolation of plant pigments

Why study photosynthesis?

Photosynthetic Antennas and Reactions Centers

Yeast Fermentation