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An Investigation to Show that Yeast Can Ferment Some Types of Sugars Quicker than Others.

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Introduction

An Investigation to Show that Yeast Can Ferment Some Types of Sugars Quicker than Others Introduction: The aim of this experiment is to show that yeast can ferment some types of sugar more quickly than others. Yeast contains enzymes (enzyme actually means 'in yeast'). Enzymes are proteins; this means that they are each made up of a unique sequence of amino acids. This is called its primary structure. This chain of amino acids then folds and twists to get into an ideal position for each of the amino acids, as they each have an 'R' group, which is either hydrophobic or hydrophilic. This process makes the amino acids into a three-dimensional shape (a third degree structure). Enzymes are catalysts, this means they speed up the rate of a reaction. For a reaction to happen, molecules known as substrates have to collide with enough energy to break and form bonds, which creates products. The energy required to make substrates is called activation energy. Enzymes lower this activation energy and therefore speed up the rate of reaction without the catalysts needing to be supplied with energy (normally this is done by heating). An enzyme can speed up a reaction by a billion times. ...read more.

Middle

I will make sure that there are no non - competitive inhibitors present by using clean apparatus. I will need to check that yeast does not produce carbon dioxide even if there is not sugar present. This will ensure that my experiment is fair and is therefore my control. I will display my results by using a bar chart to show the amount of carbon dioxide produced. Results: Test 1 Time (mins) Amount of Carbon Dioxide Produced (mm) Lactose Galactose Glucose Sucrose Fructose 2 0 0 0 0.5 1 4 0 0 0.5 2 2 6 0 0 1 4 3 8 0 0.5 2 5 3 10 1 1 3 8 4 Test 2 Time (mins) Amount of Carbon Dioxide Produced (mm) Lactose Galactose Glucose Sucrose Fructose 2 0 0 0 1 1 4 0 0 0.5 2 2 6 0 0 1 4 3 8 0 0 2 6 4 10 0.5 0.5 2.5 8 5 Test 3 Time (mins) Amount of Carbon Dioxide Produced (mm) Lactose Galactose Glucose Sucrose Fructose 2 0 0 0 0 0 4 0 0 0 1 1 6 0 0 0 2 2 8 0 0 0.5 2 3 10 0 0 1 4 3 Test 4 Time (mins) ...read more.

Conclusion

The reason for heating the mixtures was to give the particles enough energy to move around fast, enabling them to collide more often and therefore speeding up the rate of reaction, causing large amounts of carbon dioxide to be produced. On the first day I did my tests, the results were good as a lot of carbon dioxide was produced because the particles were moving around fast as a result of having been heated. On the second day however, the mixtures had not been heated properly so less carbon dioxide was being produced and the results did not correlate with the results from the previous day and were therefore anomalous. It is for this reason that I decided to omit the results from Test 3 from my averages. By the time I carried out tests 4 and 5 the mixtures had warmed up enough to produce measurable amounts of carbon dioxide so I was able to include these in my averages. My experiment would have been better if the mixtures had been heated for the same amount of time on both days, as this would have made my results more accurate. I managed to keep all the variables affecting enzyme activity the same (other than temperature, but this was accounted for) so my test was fair. 1 Steve Aston ...read more.

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