Concentration Affects the Rate of Oxygen Production When Raw Liver (catalyse), and Hydrogen Peroxide Is Mixed

Preliminary Experiment (4% yeast concentration)

Hydrogen peroxide volume – 5 cm3

Water Volume -0 cm3

Concentration Volume- 20 vols

Time in Seconds Volume of O2 (cm3)

Experiment 1 Experiment 2 Average

30 95 94 94.5

60 100 100 100

90 100 100 100

120 100 100 100

150 100 100 100

180 100 100 100

Modifications

The results from my preliminary experiment show that 100 cm3 of oxygen has been produced in the first 30 seconds.. This reaction is far too quick and will prevent me from analysing the effects different substrate concentrations have on enzymes if I decide to continue. I will therefore lower my yeast concentration to 1%. I will also measure the volume of oxygen produced every 15 seconds, instead of every 30 seconds. This will make my results more reliable and allow me to analyse my results to a higher degree.

Precautions

To ensure that my experiment is accurate I will:

• Keep the hydrogen peroxide in the brown bottle to stop it reacting with the sunlight.

• Try to minimise the handling of my equipment to prevent them warming up.

• Make sure that the bung has been placed correctly every time to stop oxygen escaping.

• Push the syringe in and out several times to make sure that no substance is left in the syringe.

Safety: Hydrogen peroxide is corrosive. To prevent accidents wear goggles and a laboratory coat. Also wipe up any spills immediately.

Results

Hydrogen peroxide volume – 5 cm3

Water Volume -0 cm3

Concentration Volume- 20 vols

Time in Seconds Volume of Oxygen O2 (cm3)

Experiment 1 Experiment 2 Average

15 14 15 14.5

30 26 27 26.5

45 40 40 40

60 53 52 52.5

75 65 64 64.5

90 74 74 74

105 80 80 80

120 85 85 85

135 90 87 88.5

150 92 90 91

165 94 93 93.5

180 94 94 94

195 96 94 95

210 96 94 95

Hydrogen peroxide volume – 4 cm3

Water Volume -1 cm3

Concentration Volume- 16 vols

Time in Seconds Volume of Oxygen O2 (cm3)

Experiment 1 Experiment 2 Average

15 11 18 14.5

30 22 24 23

45 30 33 31.5

60 38 41 39.5

75 45 49 47

90 50 54 52

105 54 58 56

120 57 60 58.5

135 60 63 61.5

150 61 65 63

165 63 66 64.5

180 64 67 65.5

195 65 67 66

210 66 67 66.5

225 66 67 66.5

240 66 67 66.5

Hydrogen Peroxide Volume – 3 cm3

Water Volume – 2 cm3

Concentration Volume – 12 vols

Time in Seconds Volume of Oxygen O2 (cm3)

Experiment 1 Experiment 2 Experiment 3 Average

15 10 12 13 12.5

30 20 22 24 23