amylase starch iodine experiment temperature

• Gunther Cox on Google+

How Temperature Affects the Ability of Amylase to Break Down Starch

• 14 test tubes
• eye droppers
• electric hot plate
• thermometers
• test tube rack
• http://wiki.answers.com/Q/How_does_temperature_affect_an_enzyme
• Personal notes on enzymes

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Practical Biology

A collection of experiments that demonstrate biological concepts and processes.

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Practical Work for Learning

Published experiments

Investigating the effect of ph on amylase activity, class practical.

Measure the time taken for amylase to completely break down starch , by withdrawing samples at 10 second intervals and noting the time at which the solution no longer gives a blue-black colour with iodine solution (but the iodine solution remains orange). Use buffers to provide solutions at different pHs . Calculate the rate of this enzyme controlled reaction by calculating 1÷ time.

Lesson organisation

This procedure is simple enough for individuals to carry out if you have enough dimple tiles. If you choose to investigate five pHs, then groups of five students could complete the investigation by working together and pooling results.

Apparatus and Chemicals

For each group of students:.

Syringes, 5 cm 3 , 2 (1 for starch, 1 for amylase)

Iodine solution in a dropper bottle ( Note 4 )

Test tube rack

Test tube, 1 for each pH to be tested

Dimple tile or white tiles

Teat pipette

For the class – set up by technician/ teacher:

Amylase 1% (or 0.5%) ( Note 1 )

Starch 1% (or 0.5%) ( Note 2 )

Buffer solutions covering a range of pH, each with a labelled syringe/ plastic pipette ( Note 3 )

Health & Safety and Technical notes

Amylase solution and iodine solution are low hazard once made up. Wear eye protection when handling iodine solution. Hazards of buffers may vary. See CLEAPSS Recipe card or supplier’s information and see Note 3 .

Read our standard health & safety guidance

1 Amylase (See CLEAPSS Hazcard and Recipe card) The powdered enzyme is HARMFUL, but solutions less than 1% are LOW HAZARD. It is wise to test, well in advance, the activity of the stored enzyme at its usual working concentration to check that substrates are broken down at an appropriate rate. Enzymes may degrade in storage and this allows time to adjust concentrations or to obtain fresh stocks. Amylase will slowly lose activity, so it is best to make up a fresh batch for each lesson; batches may vary in activity and results collected on different days will not be comparable. The optimum temperature for your enzyme will be listed on the supplier’s label.

Using saliva: the CLEAPSS Laboratory Handbook provides guidance on precautions to take (including hygiene precautions) in order to use saliva safely as a source of amylase. This has the advantage of being cheaper, not requiring technicians to make up fresh solutions each lesson, it is directly interesting to students, and salivary amylase is reliable. It also provides an opportunity to teach good hygiene precautions – including ensuring that students use only their own saliva samples (provide small beakers to spit into); that students are responsible for rinsing their own equipment; and that all contaminated glassware is placed in a bowl or bucket of sodium chlorate(I) before technicians wash up.

2 Starch suspension – make fresh. Make a cream of 5 g soluble starch in cold water. Pour into 500 cm 3 of boiling water and stir well. Boil until you have a clear solution. Do not use modified starch.

3 Buffers: (See CLEAPSS Recipe card) If you make universal buffer it will contain sodium hydroxide at approximately 0.25 M, and should be labelled IRRITANT. Refer to other relevant Hazcards if you choose to make other buffers, or to supplier’s information if you purchase buffer solutions/ tablets. ( Note 1 )

4 Iodine solution (See CLEAPSS Hazcard and Recipe card). A 0.01 M solution is suitable for starch testing. Make this by 10-fold dilution of 0.1 M solution. Once made, the solution is a low hazard but may stain skin or clothing if spilled.

Ethical issues

There are no ethical issues associated with this procedure.

SAFETY: All solutions once made up are low hazard. Wear eye protection, as iodine may irritate eyes.

Preparation

a Check the speed of the reaction with the suggested volumes of reactants to be used – 2 cm 3 of starch: 2 cm 3 of amylase: 1 cm 3 of buffer at pH 6. Ideally the reaction should take about 60 seconds at this pH: this is the usual optimum for amylase (see note 1). If the reaction is too fast, either reduce the enzyme volume or increase the starch volume. If the reaction is too slow, increase the enzyme volume or concentration or reduce the starch volume or concentration.

Investigation

b Place single drops of iodine solution in rows on the tile.

c Label a test tube with the pH to be tested.

d Use the syringe to place 2 cm 3 of amylase into the test tube.

e Add 1 cm 3 of buffer solution to the test tube using a syringe.

f Use another syringe to add 2 cm 3 of starch to the amylase/ buffer solution, start the stop clock and leave it on throughout the test. Mix using a plastic pipette.

g After 10 seconds, use the plastic pipette to place one drop of the mixture on the first drop of iodine. The iodine solution should turn blue-black. If the iodine solution remains orange the reaction is going too fast and the starch has already been broken down. Squirt the rest of the solution in the pipette back into the test tube.

h Wait another 10 seconds. Then remove a second drop of the mixture to add to the next drop of iodine.

i Repeat step h until the iodine solution and the amylase/ buffer/ starch mixture remain orange.

j You could prepare a control drop for comparison with the test drops. What should this contain?

k Count how many iodine drops you have used, each one equalling 10 seconds of reaction time.

l Repeat the whole procedure with another of the pH buffers to be used, or pool the class results.

m Consider collecting repeat data if there is time.

n Plot a graph of time taken to break down starch against pH, or calculate the rate of reaction and plot rate against pH.

Teaching notes

This is a straightforward practical giving reliable, unambiguous results. The main errors will be in the order of mixing the enzyme/ substrate/ buffer, or a delay in sampling so that the reaction time is under-estimated or rate is over-estimated. Temperature variation affects enzyme activity, so results collected on different days are not comparable.

Health and safety checked, September 2008

http://rsc.org/Education/Teachers/Resources/cfb/enzymes.htm Royal Society of Chemistry: Chemistry for Biologists: Enzymes

A clear and thorough presentation of information about enzymes as chemical catalysts and the factors affecting their activity.

(Website accessed October 2011)

Study the Effect of Temperature on Salivary Amylase Activity

• First Online: 28 February 2020

Cite this protocol

• Aakanchha Jain 4 ,
• Richa Jain 5 &
• Sourabh Jain 6  

Part of the book series: Springer Protocols Handbooks ((SPH))

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2 Citations

Enzymes are proteinaceous in nature and catalyze chemical reaction in biochemistry. Enzymes are responsible for speeding up reaction and mostly synthesized in living cells. A study of enzymatic hydrolysis of starch will give knowledge about specific reactions of enzymes. There are several factors like temperature and pH that affect the reaction. At higher temperature the enzymes are denatured, while at lower temperature, the enzymes are deactivated, so this takes more time at low and high temperature to digest the starch. At optimum temperature (32–37 °C), the enzyme is active and therefore consumes less time for starch digestion.

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Bhagyoday Tirth Pharmacy College, Sagar, Madhya Pradesh, India

Aakanchha Jain

Centre for Scientific Research and Development, People’s University, Bhopal, Madhya Pradesh, India

Sagar Institute of Pharmaceutical Sciences, Sagar, Madhya Pradesh, India

Sourabh Jain

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About this protocol

Jain, A., Jain, R., Jain, S. (2020). Study the Effect of Temperature on Salivary Amylase Activity. In: Basic Techniques in Biochemistry, Microbiology and Molecular Biology. Springer Protocols Handbooks. Humana, New York, NY. https://doi.org/10.1007/978-1-4939-9861-6_53

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DOI : https://doi.org/10.1007/978-1-4939-9861-6_53

Published : 28 February 2020

Publisher Name : Humana, New York, NY

Print ISBN : 978-1-4939-9860-9

Online ISBN : 978-1-4939-9861-6

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• CBSE Class 12
• CBSE Class 12 Biology Practical
• Study the Effect of Different Temperatures & 3 Different pH on the Activity of Salivary Amylase on Starch

Study the Effect of Different Temperatures and 3 Different pH on the Activity of Salivary Amylase on Starch

To study the effects of variation in temperature and pH levels on the activity of salivary amylase on starch.

Necessary Materials & Apparatus

• Test tubes.
• Wire gauze.
• Thermometer.
• Bunsen burner.
• Saliva solution.
• Iodine solution.
• pH tablets of 5, 6.7, 8.
• Beaker with water and a thermometer.
• 15 ml 1% starch solution + 3 ml 1% NaCl.
• 3 series of test tubes, each containing iodine solution.

Effect of Various Temperatures on the activity of salivary amylase on starch

• Divide and pour the 15 ml 1% starch solution + 3 ml 1% NaCl solution into three test tubes and name them as A, B and C.
• Pour a few ice cubes in a beaker and ensure that they stay at 5 °C.
• Transfer tube- A to the beaker with ice.
• Take two more beakers and fill them with water.
• Heat the two beakers, one up to 37 °C and the other at 50 °C.
• Ensure that the temperatures for the two beakers are constant.
• Transfer test tube B into the beaker which is set at 37 °C.
• Similarly, transfer test tube C into the beaker set at 50 °C.
• Draw 1 ml of saliva solution and add it into test tube A. Do the same for test tube B and C.
• Quickly draw a few drops using a dropper from test tube A and transfer the same to the first series of test tubes having iodine solution.
• Repeat the same: transfer a few drops from test tube B and C into the second and third series of test tubes having iodine solutions.
• Note the time as “0-minute reading” and wait 2 minutes before proceeding to the next step.
• Draw a few drops from each tube and add it to the tubes with the iodine solution. Note the change in colour.
• Repeat the experiment in intervals of 2 minutes until the colour of iodine does not change.

Effect of different pH levels on the activity of salivary amylase on starch

• Add pH tablets 5, 6.8 and 8 into test tube A, B, and C respectively.
• Now add water into a beaker and boil it by placing it on a Bunsen burner.
• Transfer all the three test tubes into boiling water.
• Use a thermometer to ensure that the temperature of this water is to be maintained at 37 °C.
• Use a dropper to transfer 1ml of saliva solution to each of the three test tubes.
• Immediately transfer a few drops from test tube A to the first series test tubes containing iodine solution.
• Repeat the same for test tube B and C, transferring the same to series 2 and 3 test tubes respectively.
• Draw a few drops from each tube and add it to the tubes with the iodine solution.
• Note the change in colour.

Observation

Effect of Various Temperatures on the activity of salivary amylase on starch: The test tube at 37 °C reaches the achromic point quickest compared to the other two. At high temperatures, the enzyme gets denatured and at low temperatures, the enzyme is deactivated. Hence, it takes more time for starch to be digested at temperatures outside 37° C.

The salivary amylase did not react in the tubes that had pH tablets of 5 and 8. It only reacted with the tube that had the pH tablet 6.8. The pH is considered acidic when it is level 5. A pH of 8 is considered to be alkaline. A pH of 6.8 s considered to be slightly acidic.

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Amylase Starch Experiments

Enzyme Model Science Projects

Amylase is an enzyme responsible for converting starches into the sugar maltose, which is a disaccharide. This enzyme, present in saliva, is a key component in germinating plants. The starches contained within the seed are converted to sugars, providing energy to the plant before photosynthesis begins. Experiments with amylase demonstrate how the enzyme reacts with starches and variables, which affect the rate of the reaction.

Chewing Bread

Bread is full of carbohydrates. Starches are considered a type of complex carbohydrate, which begins to be broken down into maltose as soon as it's in our mouths. Give each student a slice of bread that has been cut in two. The students chew one half of the bread for three minutes and write down their observations as to the changes in how the bread tastes. The other half of the bread is chewed for 10 seconds, then placed in a safe container for 10 minutes. After 10 minutes are up, the students chew the bread again. In both cases, the bread should begin to get sweeter as the amylase begins to convert the carbohydrates into maltose, which tastes sweet.

Give the students three corn seeds -- one dry, another that has been boiled, and one that has been soaked in water. The students cut the seeds in half and place the seeds on an agar petri dish that has a starch solution. The students then incubate the seeds for 30 minutes. After removal, they add an iodine solution over the plates. Starches remaining on the plate react with the iodine, creating purple areas. Students observe the differences between the seeds to determine which type of seed had more active amounts of amylase present.

As with all enzymes, amylase has a preferred pH level in which it operates. This can be determined by creating different pH levels and amylase reactions that measure the speed of the reaction. Place iodine solution drops in a test tube. In test tubes mix amylase, starch and a buffer solution with different pH levels. After mixing the solution, remove a small amount using a pipette and add it to the iodine. The iodine must turn orange when the reaction is complete. The students test the solution every 10 seconds until they arrive at the correct color. The experiment is repeated at each pH level. The pH level that turned orange the fastest is the preferred pH of amylase.

Temperature

Amylase reactions happen more rapidly at certain temperatures. Place iodine solution in a tray. Mix the amylase, starch and buffer, use the same pH this time, and test how long it takes to turn orange. Raise the temperature of the solution by 10 degrees for the next solution and retest the time it takes for the reaction to test. Students should determine the optimum temperature for the amylase reaction through multiple trials.

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Investigating the effect of temperature on the breakdown of starch by amylase.

Investigating the effect of temperature on the breakdown of starch by amylase

The aim of this experiment is to investigate how effectively the enzyme amylase breaks down starch at different temperatures, and therefore to find the optimum temperature of amylase.

Background theory relevant to this investigation involves enzymes in general, amylase itself and kinetic theory.

Enzymes are a class of proteins which catalyse chemical reactions. Unlike nonbiological catalysts such as charcoal and platinum, which often need harsh extremes of temperature and pH, enzymes must work in the mild conditions of a cell in the body, at approximately 40 o C and at a pH between 6.5 and 7.5. When compared with inorganic catalysts, enzymes are different in their rate of reaction (often 10 6  to 10 12  the rate of the uncatalysed reaction) and in their specificity, their ability to act selectively on a small group of chemically similar substances. Chemicals changed by enzyme-catalysed reactions are called the substrates  of that enzyme, and they fit into the active site of the enzyme, where the reaction takes place, in a lock-and-key mechanism. The products of the reaction then leave the active site, freeing it up for more similar reactions to take place.

Amylase is an enzyme found in various places in the body including in the saliva and in the pancreas. It acts on starch, a polysaccharide, breaking it down into maltose, a disaccharide.

Kinetic theory is the idea that, when a substance is heated, its molecules, having been supplied with energy, move around faster. In this experiment, as the temperature increases, the enzyme and starch molecules collide more frequently (Brownian motion) and with more energy which will cause them to react more efficiently. At low temperatures, the molecules will not collide very frequently and the starch will not be broken down as quickly.

It was predicted that the amylase would break down the starch most effectively at 40 o C, and with decreasing efficiency towards 0 o C, at which the amylase would be unable to break down the starch at all. This is because body temperature is around 40 o C, and enzymes are designed to work at this optimal temperature. At temperatures over 40 o C, it was predicted, the amylase would begin to denature to an extent that, at temperatures much over 50 o C, it would be totally ineffective.

I also predicted that, with time, the starch concentration would decrease for each temperature tested, showing exponential decay so that, after every x  minutes, the starch concentration would half and would therefore never be totally broken down. It was predicted that, if a graph were drawn to show starch concentration against time, it would be an exponential decay curve. The exponential behaviour was predicted because the reaction is not an equilibrium reaction: as the starch concentration decreases the enzyme finds it increasingly difficult to find enough substrate to act on. Although using iodine to test for starch would prevent a graph from being drawn in this way, the trend would still be evident.

The independent variable was temperature, controlled during the experiment. The variable dependant on this was starch concentration. All other variables therefore had to be kept constant to ensure that the experiment was a fair test. These controlled variables were concentration of amylase and starch in the solution, time period over which the experiment was conducted and the volume of amylase solution and starch solution. The apparatus was also kept the same throughout.

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I then decided to conduct the experiment as follows: Two test tubes would be taken, with equal amounts of starch and amylase solution. The contents of the two tubes would then be combined in a separate tube, and a timer started. Then, every minute, a sample of the mixture would be taken using a pipette, and placed on a ceramic tile. A drop of iodine would be added to each drop. The colour would be noted and a colorimeter used to measure the index of concentration. The index of concentration would then be noted in a table for each sample. I planned to determine the range of temperatures to test, the volumes of starch and amylase solutions to use and the concentrations of these solutions after conducting a pilot study.

After the pilot study had been carried out, I decided to use 10cm 3  of 2% starch solution and 10cm 3  of 0.01% amylase solution in the two initial test tubes for the main experiment. It proved easier to, before the experiment was started and while the starch and amylase were acclimatising, set up a tile with iodine drops already on it, in the depressions on the tile. A drop of the solution collected during the experiment could then simply be added to this and the colour noted. I also decided not to note the index of concentration, as this was impractical, and instead just to note down the time after which there was no more starch present in the solution. In order to decide at which point there was no more starch present, maltose solution was mixed with iodine in a beaker. This provided an indication of what colour the iodine would turn if there was no starch present, but there was maltose, produced by the enzyme. Based on the pilot study results, I decided to conduct the main experiment between temperatures of 20 o C and 70 o C inclusive. The pilot study showed that 20 o C was the lowest temperature at which the enzyme could function at all effectively and that the enzyme would denature possibly at 70 o C and definitely at temperatures above that. The main experiment would be conducted at 10 o C intervals between these temperatures in order to obtain a sufficient number of sufficiently dissimilar results.

Throughout the experiment, safety precautions would taken to ensure that the experiment was conducted in a safe manner: safety goggles and a lab coat would be worn at all times. All parts of the experiment would be undertaken with care, to ensure that there was no spillage. Any spillages of iodine or starch would be washed thoroughly with soap and water. If any starch solution, iodine indicator or amylase was accidentally ingested, medical attention would be sought immediately.

Obtaining Evidence

The following apparatus was used:

• Thermometers
• Water baths
• Ceramic tile with depressions

The apparatus was set up as follows:

Two test tubes were taken. One was filled with 10cm 3  of 0.01% amylase solution and the other with 10cm 3  of 2% starch solution, measured using a measuring tube. Both test tubes were left to acclimatise in a water bath at 20 o C, with a thermometer in each test tube. The tubes were checked every minute and, when both test tubes had reached 20 o C, their contents were combined in a separate, larger tube, which had also been left in the water bath. As soon as the two solutions were combined, a stop clock was started and a sample of the contents of the tube was taken using a pipette. A drop of the sample was dropped into one of the depressions on a ceramic tile, in which iodine had already been put. The colour of the iodine was noted in order to determine whether or not there was still starch present in solution in the test tube. A separate beaker was set up in which iodine solution was mixed with maltose. As maltose is produced when amylase digests starch, this would give an indication of the colour that the iodine would turn when there was no remaining starch in the test tube but just maltose. A sample was taken every minute and the same procedure repeated, until the iodine had reached the colour in the beaker, at which point it would be evident that there was no more starch. The time at which the starch had all been digested was recorded. This process was repeated twice for each of the temperatures 20 o C, 30 o C, 40 o C, 50 o C, 60 o C and 70 o C. Throughout the experiment, thermometers were used in each water bath to ensure that the temperatures remained constant.

The following results were obtained:

Analysing Evidence

In order to show the effectiveness of the enzyme rather than the time it takes to digest the starch, the inverse of the time taken to digest the starch was plotted on the y -axis, with temperature on the x -axis:

The graph shows that, between temperatures of 20 o C and 40 o C, the efficiency of the enzyme increases with temperature. However, the graph between these points is a curve so the efficiency of the enzyme is not proportional to the temperature. Between 40 o C and 60 o C, the efficiency of the enzyme decreases with temperature, mirroring the first part of the graph. The graph shows that the optimum temperature of the amylase tested was 40 o C.

The graph supports my prediction that the optimum temperature of the enzyme would be around 40 o C, and would have decreasing efficiency towards 0 o C, at which the amylase would be unable to break down the starch at all. However, the results did not support the prediction that, at temperatures over 40 o C, the enzyme would begin to denature to an extent that, at temperatures much over 50 o C, it would be totally ineffective. The reason why the enzyme seems to have been able to survive without denaturing at higher temperatures is that the enzyme used was a bacterial enzyme, and bacterial enzymes do not necessarily behave in the same way as enzymes from the human body. It therefore could have had an optimum temperature of slightly above 40 o C, and did not fully denature until the temperature was raised to 70 o C, as shown in the results table above.

It was impossible to test the prediction that, with time, the starch concentration would decrease for each temperature tested, showing exponential decay so that, after every x  minutes, the starch concentration would half and would therefore never be totally broken down. However, the results did clearly show that the starch concentration decreased with time for all temperatures except when the enzyme denatured. If a graph could have been drawn showing the concentration of starch over time for each temperature, it would probably have been an exponential decay curve.

The reason for this behaviour of the enzyme shown in the graph involves theory concerning enzymes in general, amylase itself and kinetic theory.

Kinetic theory is the idea that, when a substance is heated, its molecules, having been supplied with energy, move around faster. In this experiment, as the temperature increased, the enzyme and starch molecules collided more frequently (Brownian motion) and with more energy which caused them to react more efficiently. At low temperatures, the molecules did not collide as frequently and the starch was therefore not broken down as quickly. This is true of any reaction, whether or not it involves catalysts, biological or otherwise.

The enzyme was most effective at 40 o C because this is body temperature, at which is it most used to working. In order for it to function most efficiently in the body, amylase must have an optimum temperature of 40 o C. The reason why the amylase was less effective at higher temperatures was that it had started to denature. All enzymes start to denature at temperatures above their optimum temperatures, which renders them unable of catalysing reactions.

Evaluating Evidence

The experiment worked well overall, proving beyond reasonable doubt that the optimum temperature of the amylase used in the experiment was around 40 o C. Despite the erratic nature of the experiment, the results were sufficiently accurate that they were aligned almost perfectly on a curve, and were taken at intervals far enough apart that the readings were clearly distinguishable from each other.

However, the results were not totally accurate. For example, the first time the experiment was carried out at 70 o C, the starch disappeared in six minutes, while the second time the enzyme denatured quickly. At 60 o C, the second time the experiment was conducted at this temperature, the start took twice as long (12 minutes) to disappear. The graph was not a perfectly smooth curve, and this was due to several different factors.

The apparatus used could have been improved in many ways. The water baths used were not all at the exact temperatures required, and each contained a different amount of water. If better quality water baths had been used, and there was time to ensure that each had exactly the same amount of water and was at the exact temperature required, anomalous results could have been eliminated. This could also have been achieved by repeating the experiment for each temperature more than twice, and also by performing the experiment at intervals smaller than 10 o C. Another problem with the experiment was the use of iodine. Although iodine is a good indicator of whether or not starch is present, it does not provide accurate information about the concentration of starch present. It would have been more useful to obtain this information so that it could be plotted, to analyse how the concentration changes over time rather than at what single time there is no more starch. This quantitative approach could have been achieved by using a colorimeter. This device provides an indication of how deep a colour is, and could have been used to measure the index of concentration of the samples throughout the experiment. Values for concentration of starch in the samples could have been obtained by first recording a reading for known concentrations, then comparing these readings with those obtained with the samples collected during the experiment.

Additionally, the pipettes used were another area of error. More accurate results could have been obtained by cleaning the pipette between each reading, or using a new pipette each time, but this could not practically happen. There was always some solution left over in the pipette from the previous reason. Another problem with the pipettes was that there was time for the amylase to act on the starch while the solution was in the pipette, making the timings recorded slightly too small. However, this effect was lessened with most of the temperatures as the mixture was cooling down to room temperature in the pipette. The method by which we tested to see if there was starch remaining did not work entirely satisfactorily. Maltose was mixed with iodine to give an indication of what colour the solution would turn when there was no remaining starch, and the resulting colour was yellow. However, with the samples collected, this colour was never reached and the readings were stopped after the solution turned a yellow/brown colour and stayed that colour. Had the experiment been undertaken with greater precision, it is likely that the yellow colour would have been reached. Finally, the procedure of preparing the solutions of amylase and starch for the experiment could have been improved. It is likely that there was some solution left over from the previous repetition of the experiment, making the starch/amylase ratio different each time. This could have been overcome by washing out the test tubes between readings. The volumes of each solution could have been made more accurate by measuring the solutions using a narrower gauge measuring tube or by using a syringe.

An ideal solution would have been to automate the whole system, with a sample of the mixture being automatically taken every minute, or preferably more frequently, and the concentration of starch stored on computer. This would have overcome the inaccuracies of the timing, which could not always be exact using a stop clock and someone watching it, and would have eliminated the effect of human error from the experiment. If these steps had been taken, it is likely that a graph more similar in shape to that suggested in the prediction would have resulted.

In conclusion, the accuracy of the results was certainly good enough to make a sensible conclusion. If the experiment had been conducted under more strict conditions and with more advanced instruments, the conclusion would not have been different although the individual results might have been more accurate and the graph might have looked very slightly different.

Teacher Reviews

Here's what a teacher thought of this essay.

Stevie Fleming

** It is difficult to assess this piece of work as it seems certain key sections are missing and the pages therefore do not follow on correctly. To improve Research and rationale Examiners will be looking for a clear link between the proposed hypothesis and the biological knowledge and understanding described. In this case there needs to be a deeper discussion on the action of amylase and the biological explanation of the effect of temperature on the molecule. Suitably selected references should be included. Planning There needs to be a more thorough plan for investigation, with some explanation of the selection of apparatus and methods. (Part of the methodology section has been omitted and this makes following the report conclusions difficult). There are no details of how variables are to be controlled, manipulated or taken into account and how relevant observations are to be made. The writer needs to identify more of the potential safety hazards and the steps needed to avoid or minimise should be identified. A trial experiment should have been performed to help inform the planning. A clear hypothesis should be stated. Implementation No results table had been included and this would lose credit. It would appear from the plotted graph that a sufficient range of data had been recorded but the conclusion implies only two replicates were carried out and these seemed to have varied a great deal. A statistical test of some description or manipulation of data is normally expected at A level. Analysis and Evaluation There is only a basic enzyme explanation for the data. The discussion needs to refer to the collision theory. References to

Document Details

• Word Count 2717
• Page Count 6
• Level AS and A Level
• Subject Science

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Rate reaction between amylase and starch in different temperatures

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