Enzymes in action

Question 1

Biological washing powders often use enzymes such as:

Answer 1

• Amylase, to digest carbohydrates such as starch
• Lipase, to digest fat and remove fatty stains
• Protease, to digest protein and remove protein stains

Question 2

Biological washing powders work best at

Answer 2

Moderate temperatures because this is the optimum temperature for enzymes to work.

Question 3

After treatment with enzymes,

Answer 3

The products of digestion are soluble and so will easily wash out of the clothes.

Question 4

Biological washing powder may not work in

Answer 4

Acidic or alkaline tap water because this is not the optimum for the enzymes and they might start to denature.

Question 5

What happens to sucrose?

Answer 5

• Sucrose can be broken down by the use of an enzyme called sucrase.
• When sucrose is broken down by enzymes, the product is much sweeter, allowing the food industry to use less in food products.

Question 6

What does invertase do?

Answer 6

• Invertase converts sucrose into glucose and fructose
• Glucose and fructose are sweeter than sucrose, so less has to be added to the food, lowering the cost and the energy content

Question 7

Enzymes can be immobilised in gel beads by:

Answer 7

• Mixing the enzyme with alginate
• Dropping the mixture into calcium chloride solution.

Question 8

The immobilised enzymes produced are very useful in reactions. This is because:

Answer 8

• The mixture does not become contaminated with the enzyme
• They can be used in continuous flow processing.

Question 9

Lactose intolerance

Answer 9

Some people or animals are lactose intolerant because they cannot produce the enzyme lactase. This means that bacteria in the gut ferment lactose, which produces diarrhoea and wind.

Question 10

Milk can be treated for people who have lactose intolerance:

Answer 10

• Immobilise lactase is used to convert lactose in milk into glucose and galactose.
• Glucose and galactose can then be absorbed from the milk with no side effects