WHAT COULD YOU HAVE DONE WITH THIS LAB TO FORCE THE YEAST TO

***WHAT COULD YOU HAVE DONE WITH THIS LAB TO FORCE THE YEAST TO BE SWITCHED TO ANAEROBIC FERMENTATION? THINK REALISTICALLY ABOUT HOW THIS MIGHT BE ACCOMPLISHED.***

So basically, for this lab --> we tested different concentrations of sugar (2.5%, 5%, 10% of glucose, 5% of lactose, 5% splenda, 5% sucrose) in yeast solutions. We put the yeast and each sugar solution in test tubes and they were incubated in water baths (38-40 celcius) for 10 minutes, **uncovered. After 10 minutes, they were moved into a respiration chamber and closed immediately with the CO2 gas sensor. This then tells us the amount of carbon dioxide produced by this sugar in this yeast solution (or the rate of respiration)... so what could we have done to force the yeast to be switched to anaerobic fermentation?
Thank you!!!!!

Solution

Fermentation occurs in where oxygen is absent. After 10 minutes, they were moved into a respiration chamber and closed immediately with the CO2 gas sensor.To force the yeast to switch to anaerobic respiration we could have put a cap on the test tube.This would enclose the solution and keep the solution away from available oxygen.