Topic 1 - Core Practical - Effect Of pH On Enzyme Acivity

Question 1

What enzyme is being used in the practical to study the effect of pH?

Answer 1

Amylase

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

Question 2

What is the primary substrate that amylase acts on?

Answer 2

Starch

Starch is a complex carbohydrate that amylase breaks down into simpler sugars.

Question 3

What color does the iodine solution turn when starch is present?

Answer 3

Blue-black

The dark orange iodine solution indicates the presence of starch by changing color.

Question 4

What is the purpose of using iodine in the enzyme activity experiment?

Answer 4

To check for the presence of starch

Iodine helps to visually monitor the breakdown of starch by amylase.

Question 5

What does the practical aim to estimate regarding amylase?

Answer 5

Optimal pH

The experiment is designed to determine the pH at which amylase is most active.

Question 6

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

Answer 6

Maltose

Question 7

True or False: Amylase is active at all pH levels.

Answer 7

False

Amylase has an optimal pH range where it functions best.

Question 8

What materials are required for the experiment?

Answer 8

1% amylase solution, 1% starch solution, iodine solution, labelled buffer solutions of different pH

These materials are essential for testing the effect of pH on the activity of amylase.

Question 9

What is the first step in the experimental procedure?

Answer 9

Place single drops of iodine solution on each well of a tray

Iodine solution is used to test for the presence of starch.

Question 10

What is the purpose of placing the test tube in a water beaker above a Bunsen Burner?

Answer 10

To keep the solution at a relatively constant temperature throughout the reaction

Temperature is a control variable in this experiment.

Question 11

What should be done after adding the amylase, starch, and buffer solution to the test tube?

Answer 11

Start a stopwatch

Timing is crucial to measure the rate of reaction.

Question 12

What indicates that starch is still present in the solution?

Answer 12

The mixture turns blue-black when iodine is added

This color change indicates that amylase has not yet broken down the starch.

Question 13

What should be done if the solution is still blue-black after 10 seconds?

Answer 13

Repeat the testing process every 10 seconds until the solution remains orange

An orange color indicates that starch has been broken down by amylase.

Question 14

What is the expected optimal pH for amylase activity based on the experiment?

Answer 14

Around pH 7.0

This pH is expected to allow the reaction to complete in the shortest time.

Question 15

What should be done with the results after conducting the experiment?

Answer 15

Record results on a graph of pH (x-axis) and time taken to complete reaction (y-axis)

Graphing results helps visualize the effect of pH on amylase activity.

Question 16

Fill in the blank: The solution remains _______ to indicate that starch has been broken down.

Answer 16

orange

An orange color signifies the absence of starch in the solution.

Question 17

True or False: The Bunsen Burner is used to heat the solutions to boiling point.

Answer 17

False

The Bunsen Burner is used to maintain a constant temperature, not to boil the solutions.