Enzymes

Question 1

What are proteins made up of

Answer 1

Chains of amino acids

Question 2

What do enzymes have special shapes

Answer 2

So that they can catalyse reactions

Question 3

What happens if the temperature of an enzyme increases too much (3)

Answer 3

Some of the bonds holding the enzyme together break. This destroys the enzymes special shape. It becomes denatured.

Question 4

What happens if the pH of an enzyme is too high or low?

Answer 4

The pH interferes with the bonds holding the enzyme together. This changes the shape and denatures the enzyme.

Question 5

What is the enzyme ‘pepsin’ used for? What pH does it work best at because of this? (3)

Answer 5

Pepsin is an enzyme used to break down proteins in the stomach. It works best at pH2, which means it’s well suited to the acidic conditions there

Question 6

What do digestive enzymes do?

Answer 6

Digestive enzymes break down big molecules into smaller ones

Question 7

What does Amylase convert Starch into?

Answer 7

Sugars

Question 8

What does Protease convert Proteins into?

Answer 8

Amino acids

Question 9

What does lipase convert lipids into?

Answer 9

Glycerol and fatty acids

Question 10

Which 3 places is Amylase made in?

Answer 10

The salivary glands
The pancreas
The small intestine

Question 11

Which 3 places is protease made in?

Answer 11

The stomach (pepsin)
The pancreas 
The small intestine

Question 12

Which 2 places is lipase made in?

Answer 12

The pancreas

The small intestine

Question 13

What 2 things does bile do?

Answer 13

Bile neutralises the stomach acid and emulsified fats

Question 14

Where is bile produced? Where is it stored? Where is it realised too?

Answer 14

Bile is produced In the liver
Bile is stored in the gall bladder
Realised into the small intestine

Question 15

Bile is an alkaline. What use does this have in terms of the digestive system? (3)

Answer 15

Bile is alkaline and therefore it neutralises the hydrochloric acid in the stomach which is too acidic for enzymes in the small intestine to work properly which work best in alkaline conditions.

Question 16

Bile emulsified fats. What does this mean? How does this affect Lipase ?

Answer 16

It breaks fat into tiny droplets to give them a much bigger surface area for the enzyme lipase to work on. This makes digestion faster.

Question 17

What are enzymes used in the digestive system produced by?

Answer 17

Specialised cells in the glands and gut-lining

Question 18

What is the function of the salivary glands?

Answer 18

These produce amylase enzyme in the saliva

Question 19

What is the function of the liver?

Answer 19

The liver is where bile is produced. Bile neutralises stomach acid and emulsifies fats.

Question 20

What is the function of the gall bladder?

Answer 20

Where bile is stored before it is realised into the small intestine

Question 21

What is the function of the large intestine?

Answer 21

Where excess water is absorbed from the food

Question 22

What is the function of the rectum?

Answer 22

Where the faeces are stored

Question 23

What is the function of the pancreas?

Answer 23

Prod used protease, amylase, lipase enzymes. It realises these into the small intestine

Question 24

What is the function of the stomach (3) ?

Answer 24

1) It pummels the food with its muscular walls
2) it produces protease enzyme, pepsin
3) it produces hydrochloric acid to kill bacteria and give the right pH for the protease enzyme to work

Question 25

Why does the stomach produce hydrochloric acid? (2)

Answer 25

To kill bacteria

To give the right pH for protease enzyme to work

Question 26

What is the function of the small intestine? (2)

Answer 26

1) produces protease, amylase and lipase enzymes to complete digestion
2) where digested food is absorbed out of the digestive system into the blood

Question 27

What is meant by the optimum pH of an enzyme?

Answer 27

The optimum pH of an enzyme is the pH at which the enzyme works best

Question 28

What is a catalyst?

Answer 28

A catalyst is a substance which increases the speed of a reaction without being changed or used up in the reaction