Question 3:
We would have replaced the hydrogen peroxide samples for every trial in an ideal
experiment. This is because the hydrogen peroxide concentration decreases with time meaning
that there are fewer substrates in the solution to bond with the enzyme’s (catalase) active sites for
the reaction to take place. In later trials, our data regarding the rate of reaction would be
inaccurate and slower due to this.
Question 4:
Error 1: Environmental Temperature
In the experiment that we conducted, we did not take into account the possible variations
of the temperature in the context of its surroundings. This could possibly affect our data
substantially as catalase tends to work best at specific temperatures (37.5C). From our data, the
rate of reaction of catalase could be both higher or lower than the actual rate since the reaction
rate is dependent on the temperature which can fluctuate.
Error 2: Mass of Paper (Amount of Catalase absorbed)
Another possible error in the catalase lab could be the inconsistency of the
catalase-soaked masses of the paper disks, as different amounts of catalase were absorbed each
time. As a result, the amount of catalase remaining on the paper could vary between trials
resulting in the different masses of the paper discs. Heavier paper disks, soaked with more
catalase, could take longer to float to the top of the solution because they may be weighed down
by the excess liquid. In contrast, lighter disks with less catalase might float more quickly. Since
the floating time was used as an indirect measure of catalase activity, this inconsistency in the
masses of the paper disks could lead to inconsistent or unreliable data regarding the rate of
reaction of catalase.
Question 5:
If one's urinary system fails to operate properly, NaCl accumulates in the circulation. As a
result, NaCl would split into Na+ and Cl- ions as it enters the water present in the bloodstream.
The interactions between the charged ions Na+ and Cl- and the ionic and hydrogen bonds in the
polypeptide chain's R groups, would cause hemoglobin to denature. The structure of hemoglobin
would alter as it loses its active sites which also affect its overall function. Since hemoglobin is
responsible for carrying oxygen to the bloodstream, a loss in function would be fatal for humans.
References: Su, De-Hua, et al. "Hydrogen Peroxide: A Potential Therapeutic Target in Severe Pneumonia,
Including COVID-19?" National Center for Biotechnology Information, U.S. National Library of
Medicine, 13 May 2020,
Tan, Christopher, et al. "The Effect of Catalase on the Decomposition of Hydrogen Peroxide."
California Science & Engineering Fair, University of Southern California, 2016,
"Spectrophotometric Enzyme Assays." Creative Enzymes,