I predict that the more enzyme I use, the faster it will break up the starch to glucose. The smaller the amount of enzyme I use then the longer it will take to turn brown. I came to this conclusion by researching the following information:
Enzymes are specific – which means that an enzyme will react only with a particular molecule. There are many different enzymes. For example, an amylease only breaks down starch (carbohydrates), and a lipease will only cut down fat. An enzyme doesn’t take part in any reactions to produce the produce, only helps it happen.
There are many things that affect enzyme reactions, such as:
- Temperature – increasing the temperature gives the molecule more energy, so they move around more. This makes more collisions, therefore reacting more gluton.
- Stirring, amount of enzymes and the amount of substraight (-this is the molecule to be broken down) all either decrease or increase the number of collisions between the enzyme and the substraight.
- pH - the same denaturing happens at high or low pH. It changes the shape of the molecule. There are some that can work in high and low pH, for example, pepsin in the stomach.
From this piece of information, I now know for certain that the amount of enzyme does affect the speed in which it breaks down starch to glucose. The more enzymes, the more collisions there will be, meaning that there will be more of a reaction with the gluton.
What I did to obtain my results
- Firstly, I knew it was important to wear goggles for safety in this investigation. I also washed my hands before beginning the investigation.
- I then collected all of the apparatus I needed
- I put two drops of iodine in each dip in the spot tile
- After measuring 10ml of starch, I poured it into a test tube
- As I have chosen to have six different amounts of amylase – 1ml, 2ml, 3ml, 4ml, 5ml and 6ml. I added the first amount I planned to change - 1ml.
- I then started the stop clock. Every one-minute I took a little out and put into the iodine.
- Then, I kept doing so until it turned brown
- I recorded the time it took to turn the iodine brown (with the stop clock)
- I then repeated the experiment 3 times as I would then be able to determine an average and spot any mistakes made in the results
- Then I repeated this method, but did so using 2ml of amylase, then 3ml, 4ml, 5ml and finally 6ml.
After doing this, here are the results I collected:
Analysing my collected data
Looking at these, I now am certain that my prediction was correct – as my results show. This data proves that generally, as I increase the amount of amylease, the time it takes to react gets less. I have also studied the graph on the other page, and can come to the conclusion that the amount of enzymes definitely affects the speed it breaks down starch to glucose. It speeds the process up. I also know this is because that the more enzyme, the more collisions, which therefore reacts more gluton.
Evaluation
After looking back at the procedure I use, I think that I worked effectively enough to collect results that were correct. I think the majority of my results were completely accurate, however, there are a few that possibly may not be due to a change in the variables. I did my best to ensure that all the variable were kept the same throughout my investigation, but with things such as temperature it was difficult to be certain that there had not been slight changes. I do think that my results are reliable enough to support a firm conclusion, simply because I know I followed my method carefully and did the best I could to make sure that the experiment was kept the same throughout. I think that if any changes were to be made, I could have had a better understanding of enzymes before starting this investigation, as this may have improved my results.
In the future, I think it would be interesting to see what other things affect enzymes – such as temperature and amount of the substraight, and to what effect this would have.
