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Investigation into Pectinase

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Introduction

Investigation into Pectinase Plan: An Enzyme is a biological catalyst. This particular enzyme, pectinase, provides an alternative 'route' for the reaction that has a lower activation energy 'barrier'. Each type of enzyme has a specific 3D shape, which exactly fits the substrate with which it is reacting. The location on the enzyme where the substrate binds and the reaction takes place is known as the active site. This releases the product without damaging the enzyme so it is therefore ready to be used again. This is what happens with the enzyme when it meets and reacts: Purified pectinase is a multi-component preparation highly effective in depolymerising plant pectin's with varying degrees of esterification. Important enzymatic activities include pectin lyase (EC 4.2.2.10) and activities on polygalacturonic acid (pectin) and nonmethylated polygalacturonic acid (pectate). The result of adding Pectinase to fruit pulp means that the volume of juice taken from the fruit is increased. This is the result of the Pectin's holding fruit cells together like a chemical 'glue'. This means adding pectinase to your fruit pulp means you can extract more fruit juice than without it. A number of factors affect the rate at which an enzyme works: concentration, temperature etc. PH levels also affect the enzyme, if the level is too acidic or alkaline the 3D shape of the enzyme is altered because the conditions are too corrosive for it to keep its shape. This deems the enzyme unable to react with its specific substrate because the two shapes will no longer be able to fit together because of the one altered shape. ...read more.

Middle

In order ensure the accuracy of my results I must make sure that only the independent variable changes (the PH) and that everything else stays exactly the same. Therefore I must make sure that the same amount of apple pulp is put into each beaker, that all the beakers are incubated at the same temperature for the same period of time and that the same amount of pectinase and buffer is added to the apple pulp (2cm�). To make sure I have accurate results I must use the equipment as accurately as possible. For example, when weighing out the 40g of apple pulp I should place the beaker onto the scales first, and then press the 'tear' button to return the measurement to nought and then add the apple. That way, my results are more accurate since I'm only measuring the apple pulp this way. These might also affect the accuracy in my results. For example, there is a time gap between the enzyme and buffer being added to the pulp and the beakers being placed in the water bath. This means it will affect my results. As it will be difficult for me to stop and start the clocks at the accurate times, I will acquire some help from some fellow students which should help me be more accurate. Also the apple pulp mixture tends to stick to the side of the beaker so I would not be able to get everything into the filter paper, which would affect the results. ...read more.

Conclusion

I took all safety precautions i.e. I wore a lab coat and goggles at all times and wore gloves when handling syringes containing enzymes and PH solutions since both are irritants. I consistently weighed the apple in the same way; added ph solutions and enzymes to the pulp of both beakers at the same time and stirred the same amount of times for each PH. I was always to place and remove the beakers from the water bath at the same time as to make my results more accurate. However, if I had the opportunity to repeat the experiment again, I would do a number of things differently. I would have made sure I had a sufficient amount of time to complete the experiment and enough apparatus to carry it out accurately. Ideally, I would have completed each PH at a time, but due to restrictions this was not possible. However, despite this fact I could have arranged my time more effectively to produce more accurate results. The results I collected were not as I expected, they showed that the optimum PH for Pectinase is PH11, however I know this is incorrect. And as I explained in the first paragraph this is probably due to the fact that trials 'a' and 'b' for PH5 were significantly different therefore I have chosen to pronounce the results for PH11 anomalous. Due to the number of faults in my method as described above, some of my results may not be sufficiently accurate or reliable. I could have completed the experiment at a much higher standard to produce more precise evidence, however due to lack of time and equipment this proved difficult. 1 ...read more.

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