B2 Enzymes and Digestion (page 27)

Question 1

Enzymes used in digestion are produced by what?

Answer 1

they are produced by cells and then released into the gut to mix with food.

Question 2

What do Digestive Enzymes break down?

Answer 2

Big Molecules.

Question 3

What is classed as ‘Big Molecules’?

Answer 3

Starch, proteins and fats are BIG molecules.

Question 4

Big molecules are too big to pass through the walls of the digestive system, so what breaks them down?

Answer 4

digestive enzymes break these BIG molecules down into smaller ones like sugars.

Question 5

What do digestive enzymes break big molecules down into?

Answer 5

smaller ones like, sugars, e.g. glucose and maltose, amion acids, glycerol and fatty acids.

Question 6

Once the digestive enzymes break down the big molecules into smaller ones, what happens?

Answer 6

the smaller soluble molecules can pass easily through the walls of the digestive system, allowing them to be absorbed into the bloodstream.

Question 7

What are carbohydrases?

Answer 7

they convert carbohydrates into simple sugars.

Question 8

Give an example of a carbohydrase?

Answer 8

Amylase.

Question 9

What is Amylase?

Answer 9

Amylase is an enzyme - it can break down starch.

Question 10

Where is Amylase made in the digestive system?

Answer 10

1) The salivary Glands
2) The pancreas
3) The small Intestine.

Question 11

Give an example how starch is broken down?

Answer 11

Starch (which is a carbohydrate), &raquo_space;»> Amylase Enzyme &raquo_space;»»»>Maltose and other sugars, e.g. dextrins.

Please see diagram on page 27)

Question 12

What is Maltose?

Answer 12

a sugar produced by the breakdown of starch by enzymes.

Question 13

What is Proteases?

Answer 13

They convert Proteins into Amino Acids

Question 14

What are proteins?

Answer 14

Protein is a molecule made up of aimo acids. (proteins are needed for the body to function properely. They are the basis of body structures, such as skin and hair, and other substances such as enzymes.

Question 15

What are amino acids?

Answer 15

they are molecules that combine to form proteins. Amino acids and proteins are the building blocks of life.

Question 16

Give an example how Proteins are broken down?

Answer 16

Proteins &raquo_space;»»»» Protease enzymes &raquo_space;»»> Amino acids

Question 17

Where are Proteases made in the body?

Answer 17

1) The stomach (it’s called pepsin there)
2) The pancreas
3) The small intestine.

Question 18

Lipases convert Lipids into what?

Answer 18

Glycerol and Fatty Acids.

Question 19

What is Lipids?

Answer 19

They are fats and oils

Question 20

Give an example how Lipid is broken down in the body?

Answer 20

Lipid &raquo_space;»» Lipase enzymes&raquo_space;»»> glycerole and fatty acids

Question 21

Where are Lipases made in the body?

Answer 21

1) The pancreas
2) The small intestine.

Question 22

The body makes good use of the products of digestion. What can they be used to make?

Answer 22

new carbohydrates, proteins and lipids. and some of the glucose (a sugar) that’s made is used in respiration (see page 54).

Question 23

What is Bile?

Answer 23

Bile neutralises the stomach acid and emulsifies fats.

Question 24

Where is Bile produced?

Answer 24

in the liver.

Question 25

Where is Bile stored?

Answer 25

it is stored in the gall bladder before it’s released into the small intestine.

Question 26

The hydrochloric acid in the stomach makes the pH too acidic or alkali? and why?

Answer 26

it makes it too acidic for enzymes in the small intestine to work properely.

Question 27

Is Bile acidic or alkaline? and what do this mean?

Answer 27

Bile is Alkaline, this means it neutralises the acid and makes conditions alkaline.

(the enzymes in the small intestine work best in these alkaline conditions).

Question 28

What is meant by Bile emulsifies fats?

Answer 28

Bile breaks the fat into tiny droplets. This gives a much bigger surface area of fat for the enzyme lipase to work on - which makes its digestin faster.

Question 29

Bile is a product of the liver. Describe and explain its role in digestion? (4 marks)

Answer 29

Bile is alkaline, so it neuralises the stomach acid and makes conditions in the small intestine alkaline (1 mark)
The enzymes of the small intestine work best in these alkaline conditions (1 mark)
It also emulsfies fats/breaks down fats into tiny droplets (1 mark).
This gives a bigger surface area of fat for the enzyme lipase to work on, making digestion faster (1 mark).

Question 30

What are Lipase?

Answer 30

it is an enzyme the body uses to break down fats in food so they can be absorbed in the intestines.