I am going to make sure that my experiment is a fair test by always using the same amount of yeast and sugar solution at all times through out my experiment I shall also make sure that I am using the same sugar concentration all five times when I conduct my experiment I am also going to make sure that the water baths I am using are exactly the right temperature every time so that I don’t use the same temperature twice.
I think that when I do each of my experiments that the middle temperature of them all 4o degrees will react best as when I did my preliminary work on rennin I found that 40 degrees was the best temperature for the rennin to react, I also think this as it is the nearest of all the temperatures to our body heat of 37 degrees.
I am going to get my results by counting how many carbon dioxide bubbles come off the solution into the limewater in one minute, I will do this five times and average out my results, I will make the solution and leave it in the water bath for five minutes to equilibrate before I start doing my experiment as this is when it will react best.
I am going to repeat my investigation five times in a row at each of the five temperatures, so that I can average out all of the results and get the best results possible that I can for each temperature for this experiment.
I have decided to do this investigation every 20 degrees, the range of the temperatures I am going to use are:
Method
- At first I am going to collect all of my equipment and set it up how I need it for this experiment.
- I am then going to put on as pair of goggles and collect together all of the solutions I need for the experiment.
- I will then measure out equal amounts of the yeast solution and sugar solution and out them into a test tube.
- After that I shall measure out and put an equal amount of limewater into a test tube.
- I shall then put a bung into the top of each of the test tubes and join them together using a glass delivery tube.
- I will then put my experiment into a water bath at a certain temperature and give it five minutes to equilibrate.
- I Am then going to count how many carbon dioxide bubbles got let off in a minute, I will repeat this for five minutes to get the best results I can
- I will then repeat this whole procedure for the rest of the temperatures that I am using for my experiment recording down the average amount of bubbles let off every minute by the solution at a certain temperature.
Having finished my experiment I have looked back at my results and I have noticed that my prediction was right, I predicted that 40 degrees would be the best temperature for the yeast to react and I was right I think that this happened because yeast reacts better at a middle temperature close to body heat instead of a high heat such s 80 degrees or a low heat such as 0 degrees. I also noticed having looked at my results that the lowest temperature did not react at all and that no bubbles were given off in the five minutes I was watching it for. I also found that I had a few anomalous results (shown in blue).
I thought that my investigation worked well because I planned it all in a civilized and well ordered manner before I actually went out and did my experiment and I also think it worked well as I got as good set of results that relate just right to, my prediction.
I think that I could of improved my experiment by using scientific equipment such as a beehive shelf and a measuring cylinder instead of just counting how many carbon dioxide bubbles that were getting let off by the solution. I also think that I could of made my experiment better if I had more time as I could of investigated more of the factors that might have an effect such as the sugar concentration.
I found that my results fit the pattern well except that I found a few anomalous results (shown in blue on the table).
I don’t think that these anomalous results worked right as I don’t think that I gave the solution long enough to equilibrate so if I was to do the experiment again then I know I would have tro give the solution longer to equilibrate.
The ways in which I could improve my investigation would have to be that I gave my solution 10 minutes to equilibrate instead of 5 minutes, and I could also improve my investigation by using digital equipment, and apparatus instead of counting bubbles, I could of also used downwards displacement of the water method.
