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The planned experiment is to measure the effect on the production of apple juice from apple pulp by varying the concentration of the enzyme pectinase.

Extracts from this document...

Introduction

CONTENTS PLAN 2 Independent variables 2 Dependant Variable 2 Uncontrolled Variable 2 PRELIMINARY METHOD 3 RESULTS OF THE PRELIMINARY EXPERIMENT 4 APPARATUS 5 IDEAL METHOD 5 METHOD THAT I USED 6 PROCESSING DATA 8 RESULT ANALYSIS AND EVALUATION 8 CONCLUSION 9 RESULTS TABLE 10 GRAPH 1 11 GRAPH 2 12 Introduction The planned experiment is to measure the effect on the production of apple juice from apple pulp by varying the concentration of the enzyme pectinase. Plan An experiment to investigate the effect of the concentration of the enzyme pectinase at the rate of which juice is produced. Prediction I predict that as the concentration of pectinase increases, the rate at which the juice is produced will increase. I think that the resulting graph will look like figure 1. Below if I put my results in a table. Figure 1: predicted graph shape The graph will show that juice production will have increased as the enzyme concentration is increased. I have made this prediction like this because: Rationale Enzymes are globular proteins, which catalyse metabolic reactions. A catalyst alters the rate of a chemical reaction without itself undergoing permanent change. It can therefore be used repeatedly and so is effective in tiny amounts. Enzymes do not make a reaction happen; they simply alter the speed of ones, which already occur. As globular proteins, enzymes have a specific three-dimensional shape, which is determined by their sequence of amino acids. Despite their large overall size, enzyme molecules only have a small region that is functional. This is known as the active site. Only a few of the amino acids of the enzyme molecule make up this active site; the remainder are used to maintain its overall three-dimensional shape. The substrate molecule is held within the active site by bonds that temporarily from between the R groups of the amino acids of the active site and groups on the substrate molecule. ...read more.

Middle

% Of solution in each test tube Concentration of enzyme Concentration of distilled water 100% 8 ml 0 ml 90% 7.2 ml 0.8 ml 80% 6.4 ml 1.6 ml 70% 5.6 ml 2.4 ml 60% 4.8 ml 3.2 ml 50% 4 ml 4 ml 40% 3.2 ml 4.8 ml 30% 2.4 ml 5.6 ml 20% 1.6 ml 6.4 ml 10% 0.8 ml 7.2 ml 0% 0 ml 8 ml * Now measure the volume of distilled water of the test tube labelled 0%, which will be 8 ml, with a 5 ml pipette, and empty it into the test tube. * Do the same for each test tube and make sure you measure the distilled water accurately using a graduated pipette. * Once all the test tubes are filled with the right volume of water, fill them all with the correct volume of enzyme solution, if the enzyme sits at the bottom of the test tube, below the water, take the solution up with the pipette and let it out again, just so it mixes up. * Once all the test tubes have the correct volume of solution in them, 8 ml, check the apples, they should now look like applesauce. Place a beaker on the scales and turn the scales on. Then measure out 35.0 grams exactly of applesauce into the beaker, this is so you have the exact amount of apple pulp in each filter you do. * Fill two water baths up with warm water but hot enough to warm up the apple pulp but not too hot as to denature the enzyme. * Place the plastic test tube rack into one of the water baths and place all the test tubes in the rack. * Careful to keep and eye on the temperature with a thermometer in each test tube, not letting them go over 40%. * While these are in the water bath the applesauce should be heating up in a separate water bath and place a thermometer in there to get it to the same temperature as the enzyme solution. ...read more.

Conclusion

I don't think this is the case as my other concentrations were all increasing at roughly the same rate. The fact that the other concentrations increased at roughly the same rate supports my prediction; the enzyme will increase the amount of juice produced as the concentration of enzyme is increased. I still agree with my prediction and wouldn't change my mind as I think my results have shown that this is true except for the single one anomalous result throughout my experiment. Conclusion I conclude that my experiment has proved that the increase in the enzyme pectinase does increase the volume of juice produced. If I were to do this experiment again, I would make sure I controlled all variables that are listed at the beginning of my coursework after my introduction and plan. This would help accuracy of my results, as there would be less to affect the experiment. I would also increase the number of different concentrations, which would make the results far more accurate as I would have a bigger range to work with and get a better set of results to conclude, as per my ideal method. This would give me a more accurate picture of what is happening with the volume of juice produced and I would be able to state that it does increase the volume of juice produced with a bit more confidence and reassurance as my results would obviously be more accurate and I would be able to state more about what happened to any anomalies that occurred. Overall I think that my experiment went really well because my results weren't effected in any way as far as I can see, and I have a good set of result to analyse . I was able to read my results and see the anomalies that occurred and was able to answer my question. Although I would have liked a bit more time to do a slightly bigger range of concentrations to get results that were more accurate. Results Table Graph 1 Graph 2 ?? ?? ?? ?? Katie Scott 1 ...read more.

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