How does the change in mass of the potato affect the decomposition of
hydrogen peroxide
(this can be taken from your project proposal A)
Isnan Afridi
May 2024
,Isnan Afridi
Contents
Abstract 2
Introduction 3
Background information 4
Aims and objectives 5
Hypotheses 6
Method 6
Safety considerations 6
Apparatus 7
Instructions 7
Results 8
Results table(s) 8
Calculations 9
Graph 10
Interpretation of statistical results 11
Discussion 11
Description of results 11
Discussion of results 12
Conclusion 13
Limitations of the investigation, improvements and recommendations for further research 14
References 15
1
, Isnan Afridi
Abstract
Factors that affect the decomposition of hydrogen peroxide by biological
catalase
Isnan Afridi Year 13 , Oldham Sixth Form College(OSFC)
Brief background :
Hydrogen peroxide (H2O2) is a harmful by-product of cellular respiration, but catalase enzymes
in living cells swiftly convert it into water and oxygen, shielding cells from damage. Catalase is
chiefly found in the liver. Environmental factors like temperature and pH influence catalase
activity; optimal conditions enhance its efficiency, but extremes can cause denaturation,
rendering it ineffective.
Aim of the investigation :
The investigation aims to explore how varying masses of potato affect the rate of hydrogen peroxide
decomposition catalyzed by catalase enzymes, and consequently, the volume of oxygen produced
within 1 minute.
Method:
In this study, the relationship between the mass of potato samples and the volume of oxygen
produced was investigated using 3.3% hydrogen peroxide. Five potato cylinders were prepared by
peeling and cutting them into specified weights of 5, 10, 15, and 20 grams. These potato cylinders
were then further cut into smaller pieces to increase their surface area for better reaction. A reaction
apparatus was set up, consisting of a conical flask containing hydrogen peroxide connected to an
inverted measuring cylinder via a delivery tube to collect the oxygen gas produced. The potato
pieces were added to the hydrogen peroxide solution, and the reaction was allowed to proceed for 3
minutes. The volume of oxygen produced was recorded using a timer and measured by the
displacement of water in the measuring cylinder. This process was repeated four times for each
potato mass, and the mean volume of oxygen produced was calculated from the data.
Results:
In this study, the investigation explored the relationship between potato mass and the volume of
oxygen produced during the reaction with 3.3% hydrogen peroxide. As the potato mass
increased from 5g to 20g, there was a consistent trend of increasing average displacement
volume, rising from 10.3 to 23.0, then to 49.5, and finally to 86.0. Similarly, the standard
deviation also showed a general increase with potato mass, ascending from 2.4 to 18.4, then to
39.6, and finally to 68.8. The data exhibited variability, particularly notable with the 15g and 20g
masses, as indicated by higher standard deviations. This variability can be attributed to
fluctuations in substrate concentrations, influencing reaction rates and standard deviation
fluctuations. Overall, the observed trend of increasing average displacement volume and
standard deviation with potato mass supported the trend.
Conclusion
2