Assessment criteria: Data collection & processing. Conclusion & evaluation.
Materials:
Method
A large portion of dough is made by dissolving 4g of dry yeast in 75ml of warm water.
Add flour (about 20 spatulas) and mix it until you get a nice dropping consistency. It has to be rather wet.
Then divide the dough into 4 equal portions in small beakers.
Add two spatulas of the test substance to the dough and mix it well.
| Test tube Number | Test Substance added to dough |
| 1 | Starch |
| 2 | Sucrose (disaccharide) |
| 3 | Glucose |
| 4 | NOTHING - control experiment |
Place 3 cm of dough in the boiling tube. It is important that it is the same height in every cylinder glass.
Mark the height of the yeast, and start timing. Label the boiling tubes carefully and record the temperature of the lab.
(If everyone agreed we could do the experiment in water baths made from a beaker of warm water at 40°C and a thermometer)
Results:
Write down the height of the dough in the boiling tubes in the beginning (t=0 min) and every 5 minutes.
(Every 10 minutes if the dough raises very slow)
While you wait - make notes on the precision of the measuring equipment and qualitative observations.
Record these lab notes in a results table of your own design.Data Processing
Collect the data from all the groups in the class and collate it yourself (individually - for assessment)
Conclusion