Topic 1 - Core Practical: Effect Of PH On Enzyme Activity

Question 1

What enzyme is being studied in this practical?

Answer 1

Amylase

Amylase breaks down carbohydrates such as starch into simple sugars like maltose.

Question 2

What is the optimal pH for amylase activity expected to be?

Answer 2

Around pH 7.0

This is where the reaction is expected to complete in the shortest time.

Question 3

What color indicates the presence of starch when iodine is added?

Answer 3

Blue-black

Iodine turns blue-black in the presence of starch.

Question 4

What materials are required for the experiment?

Answer 4

• 1% amylase solution
• 1% starch solution
• Iodine solution
• Labelled buffer solutions of different pH

Question 5

What is the purpose of using a Bunsen Burner and water beaker in the experiment?

Answer 5

To keep the solution at a relatively constant temperature

Temperature is a control variable in this experiment.

Question 6

What should be recorded on the graph during the experiment?

Answer 6

pH on the x-axis and time taken to complete reaction on the y-axis.

Question 7

Fill in the blank: Amylase breaks down starch into _______.

Answer 7

Maltose

Question 8

How long should the stopwatch be started after mixing the solutions?

Answer 8

Immediately after mixing

This timing is crucial for tracking the reaction progress.

Question 9

What should be done after 10 seconds during the experiment?

Answer 9

Place a drop of the solution into one of the wells containing iodine solution.

Question 10

True or False: The iodine solution will remain orange if starch is present.

Answer 10

False

The iodine solution turns blue-black when starch is present.

Question 11

What indicates that the starch has been broken down during the experiment?

Answer 11

The iodine solution remains orange.