Experiment 4. What is the optimum t

Experiment 4. What is the optimum tempera
ture for the peroxidase reaction? (Enzyme
Data Sheet #6)
First, deal with the “technical” aspects of the work:
a) As you may recall, the Lab Manual suggested that your section pool all of its data from
this experiment to try to minimize variations in the results caused by running the
reactions at one temperature and then measuring the absorbance at room temperature. Be
prepared to share your data (
∆
A
655
/min for each temperature) with your section, and to record
others’ data.
b) Were there unexpected results for this experiment—such as two peaks on the graph of
activity
vs
temperature? If so, estimate the accuracy/reproducibility of each measurement, and
consider drawing a best-fit curve without using
the mathematical functions of Cricket Graph
(that is, by eye). Some points may be above or below the line, due to experimental variation.
Next, think about what the data tell you.
c) What was the optimum temperature for the reaction for each enzyme?
d) What is the optimum growth temperature for the plant you examined (at least, to the best
of your knowledge or according to your best ability to predict).
Reasoning from the data rather than from “what you’re supposed to get:” your data might
not match the growth temperatures of the plants. Why not? Can you explain the difference by
“technical error” in the way you did the reactions (such as using the 30
̊
water bath when you
thought you were using the 50
̊
water bath), or is the result actually valid? The result is
probably valid, since you are using data from
many replications done by each group in your
section. You have no choice but to derive your
conclusions based on your data, regardless of
your preconceived notions.