Question

Explain the student's results. The student investigated the effect of pH on the activity of amylase. He placed the same volume of starch solution in five tubes. He added different buffer solutions to each tube. He then added amylase solution to each tube. He took samples of the mixture from each tube and measured the time for all the starch to disappear. His results are shown in the table.

pH time for starch to disappear/minutes

4 did not disappear
6 8
7 4
9 14
11 did not disappear


Use the student's results to describe the effect of pH on the activity of amylase.​

Answer 1

The student's results show that amylase activity is highest at pH 6 and decreases as the pH deviates from the optimum. At extreme pH values, the amylase activity is significantly reduced or non-existent.

Step-by-step explanation:

The student's results show that the activity of amylase is dependent on the pH of the solution. From the data, we can see that the amylase activity was highest at pH 6, with a time of 87 minutes for the starch to disappear. As the pH deviated from pH 6, the amylase activity decreased. At pH 4 and 11, the starch did not disappear within the time frame of the experiment.

This pattern of activity can be explained by the fact that enzymes have an optimum pH at which they function most effectively. Amylase, like many enzymes, has an optimum pH around neutral, which is reflected in its highest activity at pH 6. Deviating from this pH optimum can lead to a decrease in enzymatic activity. At pH 4 and 11, the extreme acidic and alkaline conditions likely denatured or partially denatured the amylase, resulting in reduced or no activity.

To further support these results, it would be helpful to compare them to expected results based on previous knowledge or research on amylase activity at different pH levels.

Answer 2

The student investigated the effect of pH on the activity of amylase. They conducted an experiment using five tubes with the same volume of starch solution in each. The student added different buffer solutions to each tube to create varying pH levels. Then, they added amylase solution to each tube. Afterward, the student measured the time it took for all the starch to disappear in each tube. The results are as follows:

pH: 4 - Starch did not disappear

pH: 6 - Starch disappeared in 8 minutes

pH: 7 - Starch disappeared in 4 minutes

pH: 9 - Starch disappeared in 14 minutes

pH: 11 - Starch did not disappear

From these results, we can observe the following:

1. pH 4 and pH 11: The starch did not disappear in these two cases. This suggests that amylase activity is significantly affected at extreme pH levels, either too acidic (pH 4) or too alkaline (pH 11).

2. pH 6 and pH 7: The starch disappeared relatively quickly in these two cases, with pH 7 showing a faster reaction time. This indicates that the amylase activity is optimal or enhanced at these slightly acidic to neutral pH levels.

3. pH 9: The starch took the longest time to disappear at pH 9. This suggests that amylase activity is reduced or inhibited at this more alkaline pH level.

Overall, the student's results indicate that amylase activity is influenced by pH, with an optimal or enhanced activity observed at slightly acidic to neutral pH levels. The activity is significantly affected at extreme pH levels.

Step-by-step explanation: