Science 9 – Having previously viewed yeast budding under a microscope, students worked with me to design a new lab based on their observations.
Students noted the following observations: colour was tan, a gas was given off, there was budding, the yeast moved around (on the slide due to fluid flow).
Students then agreed that they could vary the following: amount of yeast, amount of sugar, amount of water, temperature of water, type of water/liquid, type of sugar.
From this, the experiment was designed. I had to help with the what we would use to measure or observe: by putting balloons on the flasks, the amount of gas can be compared. Students agreed to test the type of liquid (pH) and amount of sugar. This fit nicely with a lab that is written up in our textbook. Of course I was guiding them towards this 🙂
One problem with this is lab is that we have only two electronic balances for measure yeast and sugar, and our triple beam balances are not calibrated (they won’t zero properly). Measuring mass is a major time pitfall in carrying this lab out.