form d quiz

A food stain on a table cloth is where meat cooked in oil has been spilt. It is washed in a biological washing powder. Which combination of enzymes should be in the washing powder to remove the stain?

• amylase and lipase

• lipase and protease

• pectinase and amylase

• protease and pectinase

• removing the amino acids as they are formed

• increasing the amount of protein

• raising the temperature to 40 °C

• raising the pH to 7.5

Which group of compounds ensures that metabolic reactions take place effectively?

• carbohydrates

• enzymes

• fatty acids

• Hormones

Which effect does a gradual decrease in pH from 13 to 1 have on the action of amylase?

• slows it down only

• slows it down then speeds it up

• speeds it up only

• speeds it up then slows it down

Lactase is a human enzyme that catalyses the breakdown of lactose in milk. At which temperature does lactase work fastest?

• 0

• 18

• 37

• 100

• at pH 1 and pH 13

• at pH 3 and pH 11

• at pH 5 and pH 9

• at pH 7

What happens to most enzymes above 60°C?

• They are denatured.

• They are destroyed by white blood cells.

• They are digested.

• They are made more active.

What is a characteristic of all catalysts?

• They are broken down in the reaction.

• They are made of protein.

• They are not changed by the reaction.

• They do not change the rate of the reaction.

• Enzyme 1 has been changed to enzyme 2.

• Enzyme 2 slows down the production of amino acids.

• Enzymes can build up large molecules.

• Enzymes only break down large molecules.

The temperature of an enzyme-controlled reaction is increased by 10°C. How does this affect the rate of reaction?

• It always increases the rate.

• It always decreases the rate.

• It may increase or decrease the rate.

• It has no effect on the rate.