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You are required to plan a procedure that will allow you to compare quantitatively the glucose concentrations in samples of fresh orange, lemon and grapefruit.

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Introduction

Coursework plan: AS Biology You are required to plan a procedure that will allow you to compare quantitatively the glucose concentrations in samples of fresh orange, lemon and grapefruit. Introduction The experiment that I am planning involves using the Food Test for Reducing Sugars. This test is simply done by mixing an equal volume of Benedict's solution to the test solution. It is then heated in a water bath for approximately two minutes. If a precipitate has formed it shows that sugars are present. I am also going to be using quantitative Benedict's solution as weighing a precipitate will give me more accurate results. The sugar that I am finding out in the three fruits is Glucose. It has the form of a Hexose C6 H12 O6. ...read more.

Middle

One thing that I needed to know was what was the best amount of Glucose solution to put with the Benedict's solution to give the best amount of precipitate that was easy to measure. I did this simply by experimenting with different quantities of the two solutions to see which would give the best result. From this I discovered that the best mixture of the two solutions would be 5ml of the Glucose solution to 4ml of the Benedict's solution. I also had to find out what would be a suitable amount of time to leave the mixtures in the water bath for. This was simply worked out using the 4 to 5 solutions of Benedict's solution and Glucose solution. I soon discovered that the most appropriate time was approximately 2 minutes and 30 seconds. ...read more.

Conclusion

They are then heated in a water bath for approximately 2 minutes 30 seconds. These solutions are then drained through a funnel and filter paper into a 250ml beaker. The precipitate is then dried and weighed in an Oven and on Scales. We now have a range of concentrations to compare our results to. * Now we take 5ml of each of the three fruits Orange, Grapefruit and Lemon and mix each of them with 4ml of the Benedict's solution. These are then put into a water bath for again approximately 2 minutes 30 seconds. The precipitate of each is then filtered, dried and then weighed. These results can then be compared to that of the different solutions and then put in order of Glucose concentration, which is what we want to find out. Risk Assessment Hazard Risk Prevention Benedict's Solution Harmful if swallowed. ...read more.

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