- Distilled water
- Glucose
- Galactose
- Fructose
- Sorbose
It was then filled up with distilled water. Each was placed placed upside down inside a larger tube. We measured with a ruler the amount of air in the smaller tube at the start. It was then left in a water bath at 30°C for one hour to give the substances time to react. We again measured the amount of gas in the tube with a ruler and recorded the results.
Results:
A Table showing Amount of acid needed to reach the end point (ml)
Sources of error:
Conclusion:
In this experiment the yeast was broke down the sugar Fructose the fastest (see graph). This shows that yeast is most effective on Fructose than any other sugar we have used. Fructose is perhaps the sugar which yeast is specified for. The bond which all these have in common is a hydrogen stem therefore I believe that the yeast is specified for this bond, which is why it can break down similar structures containing this bond.
When the yeast respires the reaction is:
C6H12O6 2C2H5OH + 2CO2 + energy
This formulae suggests that it is the bon between the two carbons which is broken. Also supporting this is the fact that all of the sugar used had this kind of bond present. It is the elements in the molecule around the bond, which determines whether or not they can be fermentated and how well this can be done. As yeast has a specifically shaped active site like bonds can break.
Distilled water was used as a control in this experiment. As no reaction took place in the distilled water it proves that yeast can only break down similar substances to the one it is designed for (Fructose). Another control, which could have been used, would be to boil the enzyme and denature it. When the experiment did not work with the boiled yeast it would prove that there was an enzyme present.
Yes these two could be broken down as they have the same C-C bond.
