HYPOTHESES: In this exercise, the experimental hypothesis is that the reaction rate will reach an optimum above room temperature, or 23 °C, but below enzyme denaturation rate and that this maximum will be higher than the baseline rate. The null hypothesis is that there will be no differences in the reaction rates between the baseline and the temperature treatments.
Fill an 800 mL beaker about halfway to the top with ice and pour cold water into the beaker to create an ice bath. Label this beaker as “Ice”.
Then, label four new 600 mL beakers with the same temperatures as your substrate tubes and add 150 mL of tap water to each.
Using a hot plate and a thermometer, bring the beakers to 25, 35, 45 and 60 °C, as per their labels.
Prepare five more pairs of substrate and enzyme tubes, as described for the baseline reaction, using distilled water in the enzyme tube, instead of a pH buffer.
Label the substrate tubes as “Ice”, “25 °C”, “35 °C”, “45 °C”, and “60 °C”.
When all of the water baths have reached their appropriate temperatures, mix the substrate and enzyme solutions together by first pouring each substrate tube contents into an enzyme tube and then pouring the enzyme tube contents back into the substrate tube.
Cover the substrate tubes with sealing film and observe the colors at time 0.
Then, stand the tubes in their corresponding beaker baths, based on the temperature label each tube was given and start a timer.
For each 1-minute interval, remove the tubes from the water and record their color, using the stabdard as a reference.
Then, place them into their baths until each time point, up to 5 minutes, has been recorded.