4.2 - PRACTICAL - Rates of Enzyme-Controlled Reactions

Question 1

What are the 4 factors that affect the rate of enzyme reaction?

Answer 1

1. Enzyme Concentration
2. Substrate Concentration
3. Temperature
4. pH

Question 2

How can you measure the rate of reaction using hydrogen peroxide and catalase?

Answer 2

Measure the volume of oxygen gas produced in a given time.

Question 3

State the word equation for the action of catalase.

Answer 3

Hydrogen peroxide → oxygen + water

2 H2O2 → 2H2O + O2

Question 4

What are the controlled variables of this practical?

Answer 4

1. Enzyme volume and concentration
2. Substrate volume and concentration
3. PH

Question 5

State that hazards and safety precautions involved in this practical.

Answer 5

1. Hydrogen peroxide is an irritant. Wear eye protection and avoid contact with skin.
2. Take care in handling hot water baths and wash hands after handling the source of catalase.

Question 6

Outline the procedure to find the effect of enzyme concentration on rate or reaction using amylase.

Answer 6

1. Put drops of iodine solution into each well of a spotting tile.
2. Make the cereal dilution of amylase to produce several concentrations.
3. Add the same concentration and volume of starch to the first boiling tube. At the same time start the timer.
4. Use a dropping for pet to put a drop of this mixture into one of the Wells containing the iodine solution at regular intervals.
5. Time how long it takes for the color to no longer turn blue black.
6. Repeated at least two more times and calculate the mean time taken.
7. Repeat the experiment for each concentration of amylase.

Question 7

What are the controlled variables of this practical?

Answer 7

1. Temperature
2. PH
3. Substrate volume and concentration
4. Volume of enzyme added