Does respiration rate change with glucose concentration?
Suggested volume for all runs is 50mL, but students can reduce it to a minimum of 20mL. 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. Stock yeast solution should have a biological activity ranging from 45-50mg/mL. Ask your instructor for the specific biological activity. 2. Yeast need 3-5 min to begin active respiration. 3. 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. 4. Adjust the speed of the stir plate so that the solution is visibly moving to just forming a slight whirlpool. 5. A data collection table should be constructed before beginning. 6. A minimum of 10 CO2 readings or 20 sec. of data collection should be used to calculate aerobic respiration rate, AR-rate (ppm CO2/sec). 7. Remember to fan the sensor down to ambient CO2 levels below 500ppm before beginning a new run.
