How Does Temperature Affect Lipase

How does temperature affect the rate of reaction for Lipase? As the temperature increases, so will the rate of enzyme reaction. However, as the temperature exceeds the optimum the rate of reaction will decrease. I predict that at temperatures above 70 °C the enzyme lipase will become denatured and at temperatures below 10 °C the enzyme will become inactive. Since lipase operates within the human body I’d also predict that its optimum temperature would be around human body temperature which is approximately 37 °C.I predict that before the optimum temperature the rates will gradually increase and preceding the optimum there will be a drastic decrease in rate until the enzyme is denatured. I predict that the rate of enzyme activity at 45 °C will be half that of 30 °C. I predict that the rate of enzyme activity at 45 °C will be half that of 30 °C. Diagram courtesy of: http://www. rsc. org/Education/Teachers/Resources/cfb/enzymes. htm Diagram courtesy of: http://www. rsc. org/Education/Teachers/Resources/cfb/enzymes. htmIn my controlled assessment I will be investigating the activity of lipase on milk fat at various temperatures so that I can then find an accurate temperature as to when the enzyme works at its optimum; when it becomes inactive and when it denatures. To find when the enzyme denatures is to find out when the bonds of this protein disintegrate and henceforth disable the enzyme from being of any further use. When these bonds break, the protein starts to unfold and loses some its properties. For example, a denatured protein usually becomes less soluble. As an enzyme, it will lose its ability to function as a catalyst.If the stress that is causing the denaturation continues, other changes may occur. Now that the normal structure of the protein is gone, new bonds may be formed, giving it a different shape. The bonds broken in a denatured enzyme is that of which links the polymers to form the amino acids. This means that if lipase were to denature at the higher temperatures it will then cause inactivity in breaking down the fat of the milk hence leaving the unchanged. In this investigation, however, there are numerous factors as to what can affect the investigations results.First of all, the temperature of the room can play a role in altering the results as it can change the temperature of both the solution and lipase. Moreover if one were to move the solution or lipase to another part of the room, or to carry out the investigation on a different day, the temperature surrounding the solution and lipase will change and henceforth change the temperature of the solution and lipase. Secondly, if the temperature of the water bath isn’t precisely the temperature it is supposed to be then, as expected, would change.Thirdly, the age of the contents can affect the concentration of the substrates which would then decrease the rate of reaction with lipase. Finally, there is the factor of human error, as we may not be capable of making perfect measurements consistently the amounts of each component will inevitably change, which would in effect change the results. Of this investigation our independent variable will be the rate of reaction, which we will measure by timing how long it would take for the solution to turn white after having the lipase poured in.Our dependent variable will be the time it takes for the solution to turn pink after having the lipase poured in. Our controlled variable is that of will be all other factors. Enzyme Diagram courtesy of http://students. cis. uab. edu/clight/finalprojectwhatisanenzyme. html Diagram courtesy of http://students. cis. uab. edu/clight/finalprojectwhatisanenzyme. html An enzyme is a molecule that changes the speed of reactions. Enzymes can build up or break down other molecules. The molecules they react with are called substrates; enzymes are catalysts.An enzyme works by allowing a substrate, or multiple substrates, to enter the active site, which is where the reaction takes place, and then to exit in either more or less pieces then it was when it first entered. The active site is unique to a specific substrate which means that other substrates cannot react with that enzyme unless the enzyme is modified. [An active site can be altered by a non-competitive enzyme which encircles the enzyme and alters the shape of the active site which could be very dangerous. ] Diagram courtesy of: http://www. wiley. com/college/boyer/0470003790/reviews/kinetics/kinetics_effec ors. htm Diagram courtesy of: http://www. wiley. com/college/boyer/0470003790/reviews/kinetics/kinetics_effectors. htm Note that the enzyme remains unchanged so that more of the some substrates can react. Note that the enzyme remains unchanged so that more of the some substrates can react. Structure Proteins are polymers made by joining up small molecules called amino acids. Amino acids and proteins are made mainly of the elements carbon, hydrogen, oxygen and nitrogen. Pro tein Protein Amino Acid Amino Acid Each gene acts as a code, or set of instructions, for making a particular protein.They tell the cell what to do, give its characteristics, and determine the way its body works. Each protein has a unique sequence of amino acids. This means that the number and order of amino acids is different for each type of protein. The proteins fold into different shapes. The different shapes and sequences give the proteins different functions, e. g. keratin are a fibrous protein found in hair and nails. If the gene has even the slightest of disorder within its sequence it could lead to an inaccurate order of amino acids and so a faulty protein or in our case faulty enzymes.Substrate concentration An enzyme has an active site where it binds the molecule (or molecules) it acts upon; the enzyme then catalyses a chemical reaction involving that molecule (or those molecules). That molecule (or those molecules) is called the enzyme's substrate. So the substrate concen tration is the concentration of the molecules an enzyme works on. Diagram courtesy of http://biochemistryquestions. wordpress. co m/2008/07/15/induced-fit-model-of-enzyme-substrate-interaction/ Diagram courtesy of http://biochemistryquestions. wordpress. o m/2008/07/15/induced-fit-model-of-enzyme-substrate-interaction/ In general, if there is an increase in substrate concentration, then more enzymes will be catalysing the chemical reaction and the overall rate of reaction will increase. It will continue to increase until all enzymes are actively binding substrate (called saturation), at which point no further increase in rate can occur, no matter how high you raise the substrate concentration. In my investigation into enzyme response to temperature this graph will be of relevant. Diagram courtesy of: http://www. sc. org/Education/Teachers/Resources/cfb/enzymes. htm Diagram courtesy of: http://www. rsc. org/Education/Teachers/Resources/cfb/enzymes. htm Denatured Denatured Denaturing Denaturing Less kinetic energy so the reaction slows down. Less kinetic energy so the reaction slows down. This graph illustrates the response that rate of enzyme activity has at various temperatures. At lower temperatures the rate is very low as there isn’t enough kinetic energy for the enzyme to work at its optimum, then you of course have the enzymes temperature optimum where the enzyme works best at.Finally you have the denaturing of the enzyme which eventually halts with the enzyme being completely denatured where it then will never have any activity. Collision Theory For a chemical reaction to occur, the reactant particles must collide. But collisions that do not have enough energy do not produce a reaction. The particles must have enough energy for the collision to be successful in producing a reaction. The rate of reaction depends on the rate of successful collisions between reactant particles. So the less successful collisions that occurs the less products created. D iagram courtesy of: ttp://www. worthington-biochem. com/introbiochem/tempeffects. html Diagram courtesy of: http://www. worthington-biochem. com/introbiochem/tempeffects. html The reason as to why particles may have or may not have enough energy to create products depends on the amount of kinetic energy in the particles. Hence why at lower temperatures the enzyme becomes inactive as there isn’t a high enough temperature to create the necessary kinetic energy to create the products. As the temperature increases so does the rate which is due to more kinetic energy and hence more successful collisions. H An enzyme can also denature upon extreme pHs. with the extreme pH’s being 1 and 14, the enzyme would denature due to the hydrogen acids within the pH’s damaging the amino acid bonds within the enzyme. By damaging these bonds, the amino acids break apart, this in turn means that the enzyme’s active site will lose its shape, resulting in the denaturing of the enzyme. Henceforth, the optimum pH is in the middle of the pH spectrum as neutral pHs are unable to damage the bonds of the amino acids keeping the enzyme capable of reaction.Preliminary Method a. Get a test tube for each temperature being investigated. b. Add 5 drops, using a pipette, of phenolphthalein to the test tube. c. Measure out 5 cm3  of milk using a measuring cylinder and add this to the test tube. d. Measure out 7 cm3  of sodium carbonate solution using another measuring cylinder and add this to the test tube. The solution should be pink. e. Place a thermometer in the test tube. f. Place the test tube in a water bath and leave until the contents reach the same temperature as the water bath. g.Remove the thermometer from the test tube and replace it with a glass rod. h. Use the 2 cm3  pipette to measure out 1 cm3  of lipase from the beaker in the water bath for the temperature you are investigating. i. Add the lipase to the test tube and start the stopwatch. k. Sti r the contents of the test tube until the solution loses its pink colour. l. Stop the clock/ watch and note the time in a suitable table of results. *A control was also investigated by having a test tube with the sodium carbonate, phenolphthalein and milk but without the lipase.This is to test as to whether the solution would turn from pink to white regardless of whether the enzyme was present or not. This was the original method which was used to carry out the preliminary investigation, however upon consideration it was decided that for the real practical a slightly alternate method should be used. In our edited method we made the changes of firstly, on putting the lipase into the water bath, this was because heating up the solution instead is to investigate the effects of the temperature of the solution as oppose to how the temperature of the enzyme effects.Secondly it was decided upon that we would not stir the contents for two reasons: firstly because by stirring the solution it spread the lipase around more which in effect speed the reaction up so much that it was impossible to time; secondly, by stirring the contents it often made the solution over flow which both made a untidiness and caused the volume of the contents to decrease. Finally it was decided that we were to limit the amount of temperatures being investigated as temperatures below 22? the enzyme was inactive hence taking too long to record the time it took for the solution to turn white, at temperatures over 55? c the enzyme, the lipase enzyme would be denaturing hence taking too long to be able to record as well. Final Method a. Get a test tube for each temperature being investigated. b. Add 5 drops, using a pipette, of phenolphthalein to the test tube. c. Measure out 5 cm3  of milk using a measuring cylinder and add this to the test tube. d. Measure out 7 cm3  of sodium carbonate solution using another measuring cylinder and add this to the test tube.The solution should be pink. e. Plac e a thermometer in the test tube. f. Place the test tube, containing only the lipase enzyme, in a water bath and leave until the contents reach the same temperature as the water bath. g. Remove the thermometer from the test tube. h. Use the 2 cm3  pipette to measure out 1 cm3  of lipase from the beaker in the water bath for the temperature you are investigating. i. Add the lipase to the test tube and start the stopwatch. k. Stop the clock/ watch and note the time in a suitable table of results. A control was also investigated by having a test tube with the sodium carbonate, phenolphthalein and milk but without the lipase. This is to test as to whether the solution would turn from pink to white regardless of whether the enzyme was present or not. Such changes were made in an attempt to improve the validity of the investigation. As is in the nature of an investigation it is impossible to make the results completely accurate and precise. What we can do however is improve the reprod ucibility and reliability of our results by repeating the test multiple times.Risk Assessment Substance| Hazard| Risk| Risk rating*| Emergency action| Phenolphthalein | LOW HAZARD| Although it is not hazardous one should take precaution avoiding skin contamination. | 1| If in contact with eyes then flood eyes with water to wash it out. | Lipase| HAZARD| If in contact with skin it can cause an itch. If someone were to have an allergic reaction to lipase it could cause symptoms such as rashes. | 1| Seek emergency assistance if you believe you are having an allergic reaction to lipase. However wash it off as quickly as possible. Sodium Carbonate| IRRITANT| Sodium carbonate contributes to three major hazards: skin irritation, eye damage and internal effects. | 3| If swallowed, drink two or more glasses of water or milk. If in contact with skin use a cloth to wipe the sodium carbonate or rinse with water and if contact with eyes rinse thoroughly. | Milk| LOW HAZARD| If in contact with sk in it can cause an itch, however some people may have an allergic reaction to the substance. | 2| Acting in accordance to the severity of the reaction, one should wash it off as quickly as possible. Water| HAZARD| As the temperature of water we are to use will range between 10 °c-80 °c hot water may come in contact with us and burn ones skin. | 2| If hot water comes in contact with one’s skin one must rinse thoroughly with cold water to prevent further burning. | Test Tubes| HAZARD| If one were to drop a test tube, it would be very likely for it to smash, disintegrating over the floor which could then cut someone’s foot. | 2| If there is to be a broken test tube on the floor one must alert a member of staff and sweep the area whilst restricting anyone from crossing until one has finished clearing the area. Kettle| LOW HAZARD| If one were to knock a kettle over whilst boiling water the contents would spill and henceforth burn someone or something. | 1| Keep the kett le away from electrics and other peoples working areas. | *Risk rating out of /5 Generic precautions As in all practical’s one must always take precaution of what is at hand, moreover it is obligatory to wear goggles to protect the eyes and to reduce the risk of skin contact one can wear disposable gloves.Another precaution to take is to ensure that no obstacles obstruct your movement as one may then spill a substance or break a piece of apparatus, a basic step is to push in all stools and to stand up when you do a practical. In addition a class should always leave their bags at the back of the classroom and put aside planners and books making a clear workstation. Any spills, accidents or injuries should be dealt with immediately and inform a member of staff. Review of Evidence The shape of the graph resembles that of the rate of enzyme activity graph on page 3, an arc.With the shape of the graph being similar to an arc, it displays clearly that there is a definite optimum to the rate of lipase’s activity and the stages of inactivity and denaturing. The optimum temperature of lipase on this rate graph was the same in both my preliminary data and my real results data which was 30 °c and in both instances the shapes of the graphs do resemble that of an arc. In the preliminary graph, the range bars were rather extensive for example, at 35 °c the difference between the highest (non-anomaly) result and the lowest was 0. 13 in rate.These inaccurate results could have been due to multiple factors with the more obvious being either human error or faulty equipment. By having such a difference in results it only justified the changes which we had made for the real investigation. When looking back upon my original hypothesis, it stated that before the optimum temperature the rates would gradually increase due to the lack of kinetic energy provided from the heat. Upon reviewing the graph it is clearly illustrated that there is an increase in rate from te mperatures 22 °c-30 °c with an increase of 0. 26 in rate. I also predicted that the optimum temperature would be 37 °c, due to the fact that lipase operates in the human body and the human body’s temperature should be 37 °c. By analysing the evidence of which the graph presents it tells me that the highest rate of reaction was that of 30 °c, meaning this was the optimum temperature. Finally, I predicted that once the optimum was exceeded, the rates would begin to decrease as they cannot function at such temperatures due to the breaking in the peptide bonds that holds the amino acids together.Once this bond is broken, the enzyme is reduced to its primary structure which is just peptide bonds occurring – the functional structure of the enzyme is lost and it is no longer functional; denatured. After the optimum temperature, which was 30 °c, the rate of reaction began to decline as the temperatures increased. Henceforth, my prediction was right in saying that o nce the optimum temperature had been passed; the denaturing process would begin to take place, meaning the rates of reactions would become slower.Upon looking back at my quantitative prediction, which stated that â€Å"at 45 °c will be half that of 30 °c. † However, the decrease in rate was far more drastic then I had predicted. (Rate of 30 °c was 0. 032; rate of 45 °c was 0. 005. ) This means that the process of denaturing was far quicker than I had previously predicted which in turn means that my quantitative was incorrect. However, if I were to replace the 45 °c figure in my initial quantitative prediction with 35 °c it could then be plausible as the rate of 35 °c was 0. 011 (30 °c-0. 032. )In addition, I would further modify my initial prediction bySecondary data By analysing the provided secondary data I shall be able to further prove or disprove the evidence that I had recorded. By being able to prove my data with secondary data which has the same outcom e and conclusion it proves that that the data is repeatable as there are externally recorded results that support the results that I had recorded. Figure 4 courtesy of: http://www. currentscience. info/upload/IssuesFile/29_issues_Article%2010. pdf Figure 4 courtesy of: http://www. currentscience. info/upload/IssuesFile/29_issues_Article%2010. pdfFigure 3 courtesy of: http://www. google. co. uk/url? sa=t;rct=j;q=;esrc=s;source=web;cd=7;ved=0CGIQFjAG;url=http%3A%2F%2Fwww. diagnosisp. com%2Fdp%2Fjournals%2Fview_pdf. php%3Fjournal_id%3D1%26archive%3D0%26issue_id%3D31%26article_id%3D1135;ei=nrjEUJ2XC8HJ0AXPy4DACQ;usg=AFQjCNEb15WjPAyJMMgCDAjs3ZaorsN3qg;sig2=mf7h7XRNBjWBD3cdMS2v-w Figure 3 courtesy of: http://www. google. co. uk/url? sa=t;rct=j;q=;esrc=s;source=web;cd=7;ved=0CGIQFjAG;url=http%3A%2F%2Fwww. diagnosisp. com%2Fdp%2Fjournals%2Fview_pdf. hp%3Fjournal_id%3D1%26archive%3D0%26issue_id%3D31%26article_id%3D1135;ei=nrjEUJ2XC8HJ0AXPy4DACQ;usg=AFQjCNEb15WjPAyJMMgCDAjs3ZaorsN3qg;sig2=mf7 h7XRNBjWBD3cdMS2v-w Figure 1 (left) ; 2 (above) courtesy of: http://www. slideshare. net/wkkok1957/effect-of-temperature-on-lipase-activity-using-ph-sensor Figure 1 (left) ; 2 (above) courtesy of: http://www. slideshare. net/wkkok1957/effect-of-temperature-on-lipase-activity-using-ph-sensor Comparing the data sets As is clearly shown in all of the above figures there is a clear optimum. In terms of the optimum temperature, it ranges from 35 °c (figure 2 ; 3) to 25 °c (figure 4. Whereas in the recorded data that I had collated, it was 30 °c with the rate for 35 °c being significantly less than half of the rate for 30 °c. When comparing the rates at 20-25 °c another difference in rate had occurred as you can see in figures 1, 2, 3 ; 4 there isn’t such a sharp increase in rates whereas in my own results there is a steep increase in rate between 22 °c and 30 °c, a difference of 0. 026. ) Moreover, in terms of the temperature at which the lipase denatures also vari ed as the denatured point in figure 3 is at 50 °c whereas the temperature at which the lipase denatured in my investigation was at 55 °c.Finally in terms of the shape of the graphs you can see that in figure 2 the shape of the graph is of a rather steady contour oppose to the sharp point that is of my graph shape. The foremost reason as to what caused such differences was the fact that the secondary investigations used an alternate for example in figures 1 ; 2 the method utilised was slightly different as they used more accurate pieces of apparatus for example they used a micropipette to measure the sodium carbonate into the test tube which would ensure for far more accurate measurements then I had made.Secondly they used a pH probe a Logger Pro to detect the change in the milk which would also prove for much more accurate readings in comparison to detecting the change with the eye as we cannot see the entire of the solution and we, henceforth, could record a shorter or longer t ime to the actual figure as we would essentially be guessing as oppose to knowing when the reaction was definitely complete. On the contrary however, they only repeated each temperature 3 times so as to collect triplicate data.In conclusion I would say that by analysing secondary data it does support my data in its general trend but in terms of individual figures, inactivity and denatured points I am unable to defend and justify that my investigation is completely reproducible. I must say that in all, I would say that the reason as to why there is a difference in the primary data and secondary data is due to multiple factors such as alternate methods, alternate apparatus and an alternate working environment.However, in total, I do feel confident in saying that my results are reproducible to such an extent that it can resemble that of the actual figures and graph shape. Evaluation of errors I believe that the changes made to the preliminary method for the real investigation did impro ve the overall accuracy of the data in the real results data. However, in the results there were many outliers that were recorded, six in total. These errors and possible inaccuracies were made possible by such factors as human error, equipment error and technique rror. In terms of human error we may have made the mistake of timing the reaction wrong because the people who are timing the investigation may time it wrong. Secondly, there may be a difference in opinion in when the reaction would have fully completed as one may say that the solution still contains traces of pink yet another may say that the solution has no traces left. Finally, there could have been the human error of inaccurately measuring the portions of the solution.In terms of equipment error, sometimes the water baths were unable to heat the solution to the specified temperature of which were trying to investigate which would then have the effect of us collating alternate data to what we should have got, this would then alter our rate bars as they be higher or lower. Furthermore, there may no longer have been a real difference in the data’s even if there was supposed to be. Secondly, our portions of the solution may have been measured inaccurately as the measuring cylinders used may have not been accurate enough for us to get precise measurements.On top of this, whilst using the pipette to measure the contents into the measuring cylinder, air bubbles were created which then alter our results as we would then be measuring a different quantity as opposed to the proposed temperature. Finally such technique errors occurred such as the lipase may have not spread equally amongst the solution which would have left a section of the solution untouched by the enzyme. Furthermore as we took the lipase out of the water bath the temperature of the lipase would either increase or decrease if above or below the room temperature.To improve the accuracies and reliabilities of the data collected and to reduce the errors as is mentioned above I would make such alterations to the existing method: -To ensure that the lipase truly got to the temperature that it was supposed to be at an improvement would be as to set the temperature of each water bath 3 °c higher than what was prepared for which would make it easier for the lipase to heat up to the specified temperature. To increase the accuracy and eliminate the of measuring incorrectly the solution ingredients an improvement could be to use a syringe as oppose to a pipette as the pipette can’t measure as accurately as a syringe because whilst using the pipette bubbles where constantly created which made it incredibly difficult to then accurately measure the contents that were to be measured in. -As is the nature of foods and drinks the milk would eventually surpass the date hat it was meant to be consumed by. However this means that the bacteria within the milk may function in a different manner because the bacteria uses the lactose sugars to reproduce, they change it from â€Å"lactose sugar† into â€Å"lactose acid,† which tastes sour and it becomes a huge food borne illness risk to consume it and it must be discarded. Instead then we can use such alternatives as UHT or powdered milk as they have longer life spans because more of the bacteria is removed. To remove the factor of misjudgement whilst trying to detect as to whether the solution has lost all traces of pink an improvement can be to use a pH probe next time as the pH probe could then accurately detect once the reaction has completely finished by seeing when the figures stop changing on the pH probe. Improved Method a. Get a test tube for each temperature being investigated. b. Add 5 drops, using a pipette, of phenolphthalein to the test tube. c. Measure out 5 cm3  of milk using a measuring cylinder and add this to the test tube. . Measure out 7 cm3  of sodium carbonate solution using another measuring cylinder and add this to the test tube. The solution should be pink. e. Place a thermometer in the test tube. f. Place the test tube in a water bath and leave until the contents reach the same temperature as the water bath. g. Remove the thermometer from the test tube and replace it with a glass rod. h. Use the 3 cm3  syringe to measure out 1 cm3  of lipase from the beaker in the water bath for the temperature you are investigating. . Add the lipase to the test tube and start the stopwatch. k. Using the pH metre wait until it displays that no pink resides in the solution. l. Stop the clock/ watch and note the time in a suitable table of results. *A control was also investigated by having a test tube with the sodium carbonate, phenolphthalein and milk but without the lipase. This is to test as to whether the solution would turn from pink to white regardless of whether the enzyme was present or not. Evaluation of proceduresWhen analysing and evaluating the procedures I shall divide the section into fo ur sectors: precision, accuracy, repeatability and reproducibility. Precision refers to how well experimental data and values agree with each other in multiple tests. [1] The only evidence to demonstrate the precision of the data is the range bars. All range bars excluding 30 °c ;0. 001, however for 30 °c the range is ;0. 001. This proves that the precision of the data was quite good with the exception of the data for 30 °c.By having a small range in data it exemplifies precision of the data as they are all within a similar region of figures. However with 30 °c the data was rather spread meaning that the results for 30 °c degrees were not precise due to the fact that my range bar is rather spread when compared to the likes of the data from 22 °c where the range bar is a quarter of the size of the range bar for 30 °c. This provides me with the necessary evidence to believe that the rest of my results were precise, with the results for 30 °c being the exception.The abi lity to obtain consistent results when measuring the same part with the same measuring instrument. [2] Upon considering the repeatability of this investigation one can say that the results are most certainly repeatable as the data resembles that of which others have collated and that of the preliminary data. If one were to repeat the investigation with the improved method then the investigation is, with no doubt, repeatable as the evidence lies within the secondary data that supports the data of which I have collated. Accuracy refers to the correctness of a single measurement.Accuracy is determined by comparing the measurement against the true or accepted value. [3] Although there is nothing we can do to improve the accuracy per say, we can, for example, remove outliers that do not share any resemblance to that of the true value, we are able to make more accurate calculations as to what the average is because we are taking out a value that does not mean anything to the true value. B y doing so in my calculations it not only improved the accuracy of the results but it also exemplified how some factors could change the results so drastically.This demonstrates that although we can control most factors that alters the results we can’t completely control them as there are endless factors as to what can affect the results recorded, for example the room temperature could affect the results is could have heated or cooled the solution. By controlling the variables of which were possible to control we did all that was possible for us to do in order of making the investigation valid. Furthermore, by repeating the outliers again to get a new set of results it would provide for a more accurate average.This is something that was not done due to the lack of time Reproducibility is one of the main principles of the scientific method, and refers to the ability of a test or experiment to be accurately reproduced, or replicated, by someone else working independently. [4] I f the results were to be reproducible then it would be possible to look at secondary data and see that it closely resembles that of the results I have provided. When comparing my results to that of peers of who are carrying at the same investigation there is most certainly a resemblance in the overall shape of the graph.Although the rates may differ the general trend of the graph does suggest the same conclusion that there is a definite optimum at around 30 °c-35 °c. http://www. slideshare. net/wkkok1957/effect-of-temperature-on-lipase-activity-using-ph-sensor -this is a link to someone else’s investigation and results (Tony Hong), from this link you are able to see Tony’s investigation and results that follow a similar method as to mine. With this it is possible to see the results and henceforth make a conclusion as to whether my results are reproducible.By looking at his data, it displays clearly that the optimum temperature that he got was 35 °c whereas in my investigation it was 30 °c. Furthermore it seems as if that his rates seem to be considerably higher than that of mine. For example, at 35 °c the rate was 0. 011 whereas Tony got 0. 00038 (s-1. ) In conclusion, it could be said that although my graph does follow the general trend of having a definite optimum and the stages of inactivity and denaturing. However, the actual figures did vary from what I had collated meaning that my investigation’s results are most probably not reproducible.Outliers As is seen in the result tables the outliers have been circled which were then excluded when calculating the averages for it could completely change the course of the results for if they were to be used as valid results whilst calculating the average it would transform what the real results were originally presenting. Such outliers occurred due to infinite factors, however there were factors of which were attempted at being controlled as is mentioned in Page 1. Overall there was a total of six recorded anomalies, this not only had the effect of creating inaccuracies but also difficulties n detecting which figure was of the figures and which were of the anomalies. Although there was the option of using a 10% lean way which would provide for a fixed bracket as to which the figures can fall into, to what would the 10% lean way be from if we didn’t know which figure was the anomaly. The only way to resolve this problem would be to repeat the anomalies in order to attain figures which support the other figures better. Conclusion In summary I believe that the investigation that I had carried out was rather successful in that it proved that there is a definite optimum temperature as to when lipase works at its best.It also illustrated the stages of inactivity and denaturing. However, the theoretical optimum should be approximately 37 °c; the optimum that was recorded was 30 °c which would suggests that there were systematic errors. If I were to repeat th e same investigation again I would most certainly make some alterations in the method so as to improve the overall validity of the investigation. Such alterations to the method would be to use more accurate apparatus such as a pH probe to detect the reaction and a micropipette so as to improve the accuracy of the measurements of the solution contents. Bibliography http://www. lideshare. net/wkkok1957/effect-of-temperature-on-lipase-activity-using-ph-sensor -How will changing the temperature affect the rate of lipase activity of digesting milk fat into fatty acid and glycerol measured using a pH probe? 03/12/2012 Rating: A university degree investigation that seems rather professional. The investigator is an IB student. 8/10 http://www. worthington-biochem. com/introbiochem/tempeffects. html-Introduction to Enzymes. /11/2012 Rating: Worthington Biochemical Corporation was founded in 1947 for the purpose of preparing enzymes for the growing biochemical research community.The article was excerpted from a very popular Worthington publication which was originally published in 1972 as the Manual of Clinical Enzyme Measurements. While some of the presentation may seem somewhat dated, the basic concepts are still helpful for researchers who must use enzymes but who have little background in enzymology. 9/10 http://www. rsc. org/Education/Teachers/Resources/cfb/enzymes. htm –Enzyme. /11/2012 Rating: The site is aimed at students above the age of 16 who are taking Biology for further studying. It is also of use to first year undergraduates studying biology.It assumes that you have studied some chemistry. The website is supported by the Royal Society of Chemistry. 10/10 http://biochemistryquestions. wordpress. co m/2008/07/15/induced-fit-model-of-enzyme-substrate-interaction/ -Induced fit model of Enzyme-Substrate interaction. /11/2012 Rating: The biochemistry questions site is a free Biochemistry Question Bank for medical students and FMG. It is a forum where one asks a question for someone else to answer your question. It is an open source meaning that answers can derive from anywhere. 6/10 http://www. iley. com/college/boyer/0470003790/reviews/kinetics/kinetics_effectors. htm -Elementary Kinetics. /11/2012 Rating: This site is intended to supplement and extend the critical concepts presented in the Boyer textbooks. Both students and instructors at the site are encouraged to explore the world of biochemistry through multi-media. http://students. cis. uab. edu/clight/finalprojectwhatisanenzyme. html -What are Enzymes? /11/2012 Rating: Virtual chembook Elmhurst College. The site is based upon Charles E. Ophardt, Elmhurst College, findings.There is very little background to the website besides the fact that it was founded in 2003 by Charles E. Ophardt himself. 7/10 http://www. rsc. org/Education/Teachers/Resources/cfb/enzymes. htm -Enzymes. /11/2012 Rating: To see the rating for this website please look back through the bibliography to find the rating for the same website. [1] http://chemistry. about. com/od/chemistryglossary/g/Precision-Definition. htm -Precision Definition. 03/12/2012 Rating: The definition was written by Anne Marie Helmenstine, Ph. D. 10/10