Q9 Experiments Revision

What was the optimum temperature for catalase activity in the experiment?

• 0°C

• 25°C

• 40°C

• 60°C

What buffer solution produced the greatest volume of foam in the pH experiment with catalase?

• pH 4

• pH 7

• pH 9

• pH 12

How was the enzyme catalase denatured during the heat denaturation experiment?

• By boiling the enzyme solution

• By blending the enzyme

• By freezing the enzyme solution

• By adding cold ethanol

What substance was used as the immobilising gel in the enzyme immobilisation experiment?

• Sodium chloride

• Calcium carbonate

• Sodium alginate

• Glucose

Which plant is commonly used to measure the rate of photosynthesis by counting oxygen bubbles?

• Onion

• Elodea

• Busy Lizzie

• Kiwi

What is the purpose of boiling the glucose solution before adding yeast during the ethanol preparation experiment?

• To dissolve the yeast

• To remove oxygen

• To sterilise the yeast

• To increase the temperature for fermentation

Why was a water bath used in this experiment?

• To boil the enzyme

• To provide constant and controlled temperature conditions

• To keep the enzyme solution sterile

• To denature the enzyme

What was used as an indicator to show the production of oxygen gas in the pH experiment?

• Ethanol

• Washing-up liquid

• Benedict’s solution

• Iodine solution

What was observed in the test tube containing boiled catalase?

• Production of foam

• Color change to purple

• No foam production

• Precipitate formation

What advantage does an immobilised enzyme offer over free enzymes in industrial processes?

• Higher reaction rate

• It works at a wider range of temperatures

• It dissolves easily in the substrate

• Enzyme can be reused, and no product separation is needed