APBiologyCollege BoardTopic Questions3. Cellular Energetics3.3 Environmental Impacts on Enzyme Function

Environmental Impacts on Enzyme Function (College Board AP Biology)

Topic Questions

DownloadView
Medium
1a4 marks

An experiment was conducted to measure the reaction rate of the human salivary enzyme α-amylase. Ten mL of a concentrated starch solution and 1.0 mL of α-amylase solution were placed in a test tube. The test tube was inverted several times to mix the solution and then incubated at 25°C. The amount of product (maltose) present was measured every 10 minutes for an hour. The results are given in the table below.

Time (minutes)  Maltose Concentration (μM)
0 0
10 5.1
20 8.6
30 10.4
40 11.1
50 11.2
60 11.5

 

Graph the data on the axes provided and calculate the rate of the reaction for the time period 0 to 30 minutes. 

How did you do?

1b2 marks

Explain why a change in the reaction rate was observed after 30 minutes. 

How did you do?

1c2 marks

Draw and label another line on the graph to predict the results if the concentration of α-amylase was doubled. Explain your predicted results. 

How did you do?

1d4 marks

Identify TWO environmental factors that can change the rate of an enzyme-mediated reaction. Discuss how each of those two factors would affect the reaction rate of an enzyme. 

How did you do?

Did this page help you?

2a1 mark

Fireflies emit light when the enzyme luciferase catalyzes a reaction in which its substrate, D-luciferin, reacts to form oxyluciferin and other products (Figure 1). In order to determine the optimal temperature for this enzyme, scientists added ATP to a solution containing D-luciferin, luciferase, and other substances needed for the reaction. They then measured the amount of light emitted during the first three seconds of the reaction when it was carried out at different temperatures.

D-Luciferin + O2 + ATP rightwards arrow with Luciferase on top Oxyluciferin + CO2 + AMP + PPi + Light

Figure 1. Light is emitted as a result of the reaction catalyzed by luciferase.

Describe a characteristic of the luciferase enzyme that allows it to catalyze the reaction.

How did you do?

2b1 mark

Identify the dependent variable in the experiment.

How did you do?

2c1 mark

State the null hypothesis for the experiment.

How did you do?

2d1 mark

A student claims that, as temperature increases, there will be an increase in the amount of light given off by the reaction in the first three seconds. Support the student's claim.

How did you do?

Did this page help you?