Food and digestion

Question 1

Name the nutrients we require from our food.

Answer 1

Carbohydrates, Fibre, protein, fats, vitamins, minerals, water

Question 2

Why should we eat a variety of foods?

Answer 2

Different foods contain different amounts of each nutrient and foods may not contain all nutrients.

Question 3

What is a balanced diet?

Answer 3

A balanced diet contains the correct amount of each of the seven nutrients.

Question 4

What do Carbohydrates supply us with?

Answer 4

energy

Question 5

What carbohydrate gives us fast releasing energy

Answer 5

sugars

Question 6

What carbohydrates give us slow releasing energy

Answer 6

starches

Question 7

What does fibre do?

Answer 7

Fibre helps our digestive system by adding bulk to our food and aiding its movement along our digestive tract

Question 8

What does protein do?

Answer 8

Proteins help us to grow and help us to repair body tissues

Question 9

What do fats do?

Answer 9

Fats provide us with energy that can be stored. Fats help to provide insulation

Question 10

What do vitamins and minerals do?

Answer 10

Vitamins and minerals help to prevent certain diseases

Question 11

What do we need water?

Answer 11

Water is needed for chemical reactions and helps to transport materials around our body.

Question 12

What occurs when the diet does not supply us with the correct amount of each of the seven nutrients.

Answer 12

Malnutrition

Question 13

What is a deficiency disease?

Answer 13

a deficiency disease is caused by a lack of a particular nutrient in the diet.

Question 14

Scurvy is caused by

Answer 14

Lack of vitamin C

Question 15

Kwashiorkor is caused by

Answer 15

Lack of protein

Question 16

Anaemia is caused by

Answer 16

Lack of iron

Question 17

Rickets is caused by

Answer 17

Lack of vitamin D or Calcium

Question 18

What may be caused caused by vitamin A deficiency?

Answer 18

night blindness

Question 19

How do we know what nutrients foods contain?

Answer 19

Samples of food can be tested to see which of the different nutrients they contain.

Question 20

How do we test a food for the presence of starch?

Answer 20

Iodine solution is used to test for starch.

Question 21

What is the colour change we notice when testing for the presence of starch?

Answer 21

Iodine changes colour from reddish-brown to blue-black.

Question 22

How do we test a food for reducing sugars.

Answer 22

Benedict’s solution is used to test for reducing sugars.

Question 23

What happens to Benedict’s solution in the presence of reducing sugars?

Answer 23

In the presence of a reducing sugar Benedict’s solution changes colour from blue to orange.

Question 24

What do we use to test a food for protein.

Answer 24

Biuret’s solution is used to test for protein.

Question 25

Describe a positive test for protein.

Answer 25

In the presence of protein Biuret’s solution changes colour from blue to violet.

Question 26

What subunits are complex carbohydrates made from?

Answer 26

Complex carbohydrates (such as starch) are made up of many small units called sugar molecules (glucose).

Question 27

What subunits are proteins made from?

Answer 27

Proteins are made up of many small units called amino acids.

Question 28

What subunits are fats made from?

Answer 28

Fats are made up of subunits called fatty acids and glycerol.

Question 29

What do we use to mechanically breakdown food in our mouth?

Answer 29

Humans use their teeth to bite and chew food, mechanically breaking the large pieces down into smaller ones.

Question 30

Which teeth are used for ripping and tearing food?

Answer 30

Canines for ripping and tearing

Question 31

Which teeth are used for cutting and slicing food?

Answer 31

Incisors for cutting and slicing

Question 32

Which teeth are used for chewing and grinding food?

Answer 32

pre-molars and molars for chewing and grinding.

Question 33

Describe the process of digestion.

Answer 33

Digestion is the process by which large insoluble molecules are broken down chemically into small soluble molecules that can be absorbed into the bloodstream.

Question 34

What is the alimentary canal?

Answer 34

the alimentary canal is a long muscular tube running from the mouth to the anus

Question 35

Which part of our digestive system has layers of muscles which cause contractions, mixing food with acid?

Answer 35

The stomach has layers of muscle that contract and relax and cause it to churn the food. This mixes the food with many digestive juices.

Question 36

Where are products of digestion are absorbed into the bloodstream.

Answer 36

The products of digestion are absorbed into the bloodstream through the wall of the small intestine.

Question 37

What makes the small intestine suitable for its role in digestion?

Answer 37

Its very long, highly folded with a large surface area for absorption. It also has many blood vessels.

Question 38

Which part of our digestive system absorbs water from undigested food?

Answer 38

The large intestine absorbs water from the remaining undigested food material.

Question 39

What is the waste product of digestion known as (scientifically)?

Answer 39

Faeces

Question 40

What molecules are found in digestive juices and help speed up the porcess of digestion?

Answer 40

Digestive juices contain enzymes which are special protein molecules made in our cells that help to speed up chemical reactions.

Question 41

What is meant by enzyme specificity?

Answer 41

Each biological reaction has its own specific enzyme

Question 42

What is a substrate?

Answer 42

The substance an enzyme acts on is called its substrate

Question 43

What is a product of an enzyme reaction?

Answer 43

The substances produced during the reaction are called products

Question 44

Why can the enzyme be used again for another reaction?

Answer 44

The enzyme has not been changed which means that it can be used again

Question 45

What does the enzyme amalase break down?

Answer 45

Amylase speeds up the breakdown of starch into simple sugars.

Question 46

Where is amylase produced?

Answer 46

Amylase is produced by cells in the salivary glands and in the pancreas.

Question 47

What does the enzyme protease break down?

Answer 47

Protease speeds up the breakdown of protein into amino acids.

Question 48

What does the enzyme lipase break down

Answer 48

Lipase speed up the breakdown of fats into fatty acids and glycerol.