|Aerobic respiration is the key metabolic process of
producing cellular energy in eukaryotic and some prokaryotic cells.
|1. Develop a hypothesis and design an experiment on
aerobic respiration of a single cell organism, yeast
2. Examine various components of the respiratory pathway such as Carbon source (substrate concentration), temperature, and metabolic factors can affect respiration rates.
|1. How many ways could you measure aerobic respiration?
2. Do plants undergo aerobic respiration? What cell organelle would a plant need for respiration? Would a fungus have the same or a different organelle?
3. How does temperature relate to respiration rate? Is it similar to the effects observed with enzyme activity?
4. How could you measure the effects of the various pathway components on the rate of aerobic respiration?
|Campbell: pp. 147-153
CO2 Sensor Operation
Suggested volume for all runs is 50mL, but students can reduce it to a minimum of 20mL.
Directed Investigation-How much yeast is needed to get a respiration rate of 500-800ppm CO2/min?
1. Yeast should be suspended in no more than 100mM glucose by diluting your stock solution. The final volume should be no more than 50mL.
2. Add varing amounts of yeast to your glucose solution and record the yeast concentration in mg yeast/mL. Begin with a dilution range of 1/10 to 1/100.
3. Yeast need at least 5 min to begin active respiration.
4. Add respiring yeast to a clean 125mL flask with a stir bar just before data collection to avoid flask from building up high levels of CO2.
5. Adjust the speed of the stir plate so that the solution is visibly moving to just forming a slight whirlpool.
6. A data collection table should be constructed before beginning.
7. A minimum of 10 CO2 readings or 2 min. of data collection should be used to calculate aerobic respiration rate, AR-rate (ppm CO2/min).
8. Remember to fan the sensor down to ambient CO2 levels below 500ppm before beginning a new run.
1. Select the CO2 sensor from the Vernier Experiment file.
2. Under Sensor menu, set up the sensor to record time in minutes
3. Sample 10-12X/min or every 10 sec. Every 5 sec is OK.
4. Duration 3-5 min or stop if ppm is 4500 or greater. Sensor limit is 5000ppm.
|Based on your groups preliminary results and
observations, develop a group hypothesis and detailed experimental design to study aerobic
respiration in yeast. Your design should answer the following questions:
Design and perform one of the following investigations
Complex C source
|Students need||a working 3.5 in floppy disk. Bring several to check,
Your experimental design.