Diana Duka
Unit 6
Assignment C&D
Investigative Project
C: Safely undertake the project, colleting, analysing and presenting the results.
D: Review the investigative project using the correct scientific principle.
Introduction
The report contains thorough investigation of the effect of temperature on pectinase enzyme.
All results are analysed, compared to other literature as well as discussion of limitations and
improvements to provide a detailed report about the chosen enzyme and any trends noticed
during the experiment. The results from the experiment were recorded into a table.
Demonstration of Practical Skills - P4
Investigating the Effect of Temperature on Pectinase enzyme catalyse break down of Pectin.
Hypothesis
The pectinase will provide a faster extraction and larger volume of the juice obtained from
the apple pulp as the temperature is increased from room temperature to the enzyme’s
optimum temperature. The volume of apple juice collected at its optimum temperature will
have a significant difference of volume compared to the juice collected at room temperature.
The enzyme, pectinase, catalyses the pectin found in the apple pulp faster at 50℃, as the
particles within the protein experience the greatest amount of kinetic energy. The enzyme
activity will decrease after the maximum temperature is reached, as the active site of the
enzyme denatures, meaning pectin cannot bind to the enzyme.
Equipment
● 100ml beakers (x8)
4 beakers are used to heat the apple pulp and 4 beakers are used to heat the
pectinase enzyme.
● 2ml syringe
Used to measure 0.5ml of pectinase
● 25ml measuring cylinders (x4)
, Each measuring cylinder will collect the volume of apple juice from the different
temperatures.
● Small funnels (x4)
Required to allow the muslin cloth to be placed inside the funnel to collect smooth
apple juice.
● Glass stirring rods (x4)
Can be any kind of stirring rod. Required to mix the heated pectinase and apple pulp.
● Muslin cloths (x4)
Required to filter the mixture, so only juice is collected.
● Stopwatch
To measure the amount of time the pulp and enzyme is being heated, the mixture is
left to cool and the time it takes for juice to be collected.
● Water baths (x3)
Each water bath must be at different temperatures - 30,40 and 50℃.
● Thermometers (x9)
Some thermometers must be placed into the water baths to control the temperature,
some are placed into the beakers containing apple pulp and some are placed into
beakers containing enzymes to observe if it has reached the correct temperature.
● Digital Scale
To measure the amount of apple pulp needed for the experiment.
● Spatula
To scoop the apple pulp from the container.
Risk Assessment
Risk Hazard Precaution
Pectinase enzyme solution Minor skin or eye irritation - Wash hands and eyes
spillage thoroughly if pectinase
solution has come into
contact with the skin or
eyes.
Utilising glass equipment Minor cuts, grazes and/or - Use glass equipment with
(glass stirring rod, beaker, glass equipment breaking. extra care and attention.
thermometer) - Place equipment away
from the table edge.
,Variables
● Control variable - time (beakers are left in the waterbaths for the same amount of
time)
- Weight (apple puree is measured to the same amount)
- Volume of pectinase solution (measuring 0.5ml of pectinase, using 2ml
syringe)
- Concentration of enzyme (2% of pectinase enzyme)
● Independent variable - temperature (the effectiveness of pectinase will be tested at
20, 30,40,50 and 60℃)
● Dependent variable - volume of apple juice extracted
Method
1. Collect all the equipment required and set up the water baths at 30, 40 and 50℃.
2. Measure the weight of each beaker using the scale provided. Note the weights down.
3. Using a digital scale, measure out 15 grams of apple pulp. Use a spatula to scoop
the desired amount, making sure that the beaker’s weight is taken into consideration.
Repeat in 4 different beakers.
4. Take 4 new 100ml beakers. Using a 2ml syringe, measure out 0.5ml of pectinase 4
times and place into each beaker.
5. After labelling the beaker with the temperature they are going to be put in, place one
beaker of apple pulp and one beaker of pectinase into the water bath set to 30℃.
Repeat with each beaker so it is in all water baths. Leave one beaker of apple pulp
and enzyme at room temperature.
6. Start the stopwatch and keep the beakers in the water baths for 10 minutes.
7. While the substance warms, set up 4 measuring cylinders. Place a funnel into the
measuring cylinder and cover with the muslin cloth.
8. Pour the heated pectinases into the heated apple pulp. Mix with a glass stirring rod
9. Wait 5 minutes for mixtures to cool before pouring it through the funnels.
10. Note down the millilitres of apple juice collected at 20 minutes.
Collection, Analysis and Presentation of Results - P5
Temperature Volume of apple juice created (ml)
(℃ Celsius)
Trial 1 Trial 2 Trial 3 Mean
20 5.35 5.00 5.20 5.18
, 30 5.60 6.00 7.00 6.00
40 4.95 5.60 4.80 4.88
50 5.75 2.80 6.00 5.88
[Results and Results Table from Logbook]
The table above was used to collect my data from my investigation. It can be seen that the
temperatures of 20, 30, 40 and 50 ℃ were measured and obtained along with the volume of
apple juice extracted in millilitres. The mean was also calculated to show any anomalies,
trends and most importantly to prove that the optimum temperature researched was reliable
and accurate. However, it should be noted that the mean does not include any anomalies.
It can be seen that at Trial 2, there are two anomalies; one at 40 ℃ and the other at 50 ℃,
which was due to beakers being pushed over by hydrostatic pressure, thus affecting the
results that were obtained. There was an increase in apple juice extracted at 40°C during
Trial 2, as the beaker was left in the waterbath for a longer period of time. Also, during Trial
2, at 50℃ it can be seen that the volume of juice extracted after heating has significantly
decreased as the beaker was pushed over several times, which has required me to
remeasure and reheat the contents, however there was not enough time to do so.
[Bar Chart and Error Bars of Mean Apple Juice Extracted (ml) at Different Temperatures,
created in Google Sheets]
The bar graph illustrates the mean apple juice collected at different temperatures, including
the error bars. It can be stated that at temperatures 30°C and 50℃, the enzymatic activity is
similar, along with how spread out the data is at the two temperatures. This could be due to
the rate of reaction, as the optimum temperature of pectinase ranges between 40℃ to 50°C.
