Enzymes

• a

• b

• c

• d

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

A carbohydrates

B enzymes

C fatty acids

D hormones

• a

• b

• c

• d

• a

• b

• c

• d

• a

• b

• c

• d

• a

• b

• c

• d

• a

• b

• c

• d

• a

• b

• c

• d

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

• a

• b

• c

• d

Lactase is a human enzyme that catalyses the breakdown of lactose in milk.

At which temperature does lactase work fastest?

A 0 °C B 18 °C C 37 °C D 100 °C

• a

• b

• c

• d