What is the effect of particle size of coffee on the time taken for the pressure to reach 130kPa when hydrogen peroxide is broken down by catalase in potato?
Independent Variable: surface area of ground coffee
Dependent Variable: rate of gas pressure increase (in kPa/s)
Independent Variable: surface area of ground coffee
Dependent Variable: rate of gas pressure increase (in kPa/s)
method
1.Brew the coffee as indicated in earlier steps
2.With a cork borer cut cylinders from
potato. Place a ruler beside the cylinder and cut the cylinder into 120 discs
3mm thick.
3.Set up the apparatus as shown below with
10 potato discs.
4.Add 10cm3 of the brewed coffee from beans
or water in the control and
5cm3 of
pH7 buffer to the test tube
5.Allow it to settle for 5 minutes
6. Change the data logger settings for 1
sample every second for 300
seconds.
7.Dilute the hydrogen peroxide with 50cm3 of distilled water and 50cm3 of 5 volume hydrogen peroxide
8.Connect
the test tube’s delivery tube to a gas pressure sensor
9.From the syringe, add 10cm3
of hydrogen peroxide turn on the tap add the syringe and then turn off the tap
10.Leave this for 500 seconds
11.Repeat steps 6-13, 3 times
12.Repeat steps 6-14 for each of the
different ground coffee with the different surface areas
Risk
Assessement:
Hydrogen peroxide is an irritant à use googles and lab coat
Cork borer can cause injury in hand à use a white tile
Bung of test tube may pop à use goggles, point the test tube away from people
Scalpel can cause injury à use white tile
Hydrogen peroxide is an irritant à use googles and lab coat
Cork borer can cause injury in hand à use a white tile
Bung of test tube may pop à use goggles, point the test tube away from people
Scalpel can cause injury à use white tile
Conclusion
Coffee inhibits catalase activity
Found no online resource
Coffee is slightly acidic à slightly changes structure of enzyme
Coffee inhibits catalase activity
Found no online resource
Coffee is slightly acidic à slightly changes structure of enzyme
Evaluation
Wouldn’t use a pH buffer
Use a conical flask
Wouldn’t use a pH buffer
Use a conical flask