An experiment on the effects of temperature on the rate of respiration of yeast.?

Question

What is an simple experiment that can be done at home to determine the effects of temperature on the rate of yeast respiration?

Answer 1

Take two identical bottles, fill them with identical amounts of HOT or COLD water, add identical amounts of sugar (1tsp or 1tbsp, whatever you feel is right), add identical amounts of yeast, and put identical balloons over the tops of the bottles. Tie the balloons on tightly with rubber bands, if necessary.

Now you can wait a certain length of time - 15-20 minutes sounds reasonable - and then measure the diameters of the balloons at the widest part with a string, and measure the length with a ruler.

The bigger the diameter - the more inflated the balloon - the more CO2 the yeast has made, and the faster it has respired (in that time frame).

Make sure the water is hot but not boiling though, or you'll kill the yeast and melt your plastic bottle.