Video Transcript
The enzyme catalase catalyzes the
reaction that breaks down hydrogen peroxide into water and oxygen. The graph shows how much oxygen is
produced over time when this reaction occurs with and without catalase. Which of the following statements
correctly describes the trend shown? (A) The reaction produces more
oxygen when catalase is present. (B) The reaction produces oxygen at
a quicker rate when catalase is present. (C) The reaction produces oxygen at
a quicker rate when catalase is not present. (D) The reaction produces more
oxygen when catalase is not present. Or (E) there is no correlation
between the rate of oxygen production and the presence of catalase.
Let’s remove our answer choices so
we have more space to work out the answer to our question. Our question introduces a specific
enzyme called catalase. Catalase is involved in the
conversion of hydrogen peroxide into water and oxygen. This enzyme is especially important
for converting harmful byproducts of cellular respiration, like hydrogen peroxide,
into less harmful molecules. The question also presents a graph
of how much oxygen is produced in the presence and absence of the catalase
enzyme.
You might remember that the rate of
the reaction can be determined by the slope of the line on our graph. A steeper slope is equivalent to a
higher rate of reaction. The rate of oxygen production is
increased in the presence of catalase because catalase is an enzyme. You may remember that enzymes are
often called biological catalysts because they speed up reactions. You may also notice that the
reaction with catalase levels out after about a minute. This is because all of the hydrogen
peroxide was converted. Catalase speeds up the conversion
of hydrogen peroxide to water and oxygen. So it produces oxygen and water at
a faster rate than a reaction without catalase.
Now that we have reviewed the
graph, let’s bring back our answer options so we can decide on the correct
answer. Because oxygen is produced at a
faster rate when catalase is present, the correct answer to our question is answer
choice (B). The reaction produces oxygen at a
quicker rate when catalase is present.
