The document provides information about the digestive system and nutrition. It begins with an introduction to the digestive system and explains the four main stages of nutrition: ingestion, digestion, absorption, and excretion. It then discusses the process of digestion in more detail, explaining that digestion breaks down food into smaller particles that can be absorbed and passed through cell membranes. Various digestive organs like the mouth, stomach, and small intestine are involved in digestion. Tests are also described to identify different food types like starch, sugar, protein, and fat. Maintaining a balanced diet with a variety of food groups is emphasized as important for health.

1. 
Food for Life
Year 9
N Gibellini
1

2. http://lgfl.skoool.ccoo..uukk//kkeeyyssttaaggee44..aassppxx??iidd==885500
2

3. SLOs

3

4. Introduction

 http://lgfl.skoool.co.uk/content/keystage3/biology/pc/learningsteps/ http://www.bbc.co.uk/learningzone/clips/a-well-balanced- http://e-learningforkids.org/Courses/EN/S0702/launch.html
4

5. SLO

Appreciate that a balanced diet is
essential for good health
5

6. Why do we need food?
We need food for: 
Storage of energy as fat, insulation
Growth of new tissues
Repair of damaged tissues
Movement
Heat
Chemical reactions
6

7. Eat Healthy Kids!

7

8. My Energy Balance
The amount of energy I require each day is
11,550 kj or 11.55 MJ
In the last 24 hours I ate:
Item of
Food
Amount Approximate
number of kj
Approximate
number of MJ
Total
8

9. My total energy input for the last 24 hour is _____ kJ, or ____
MJ

1.Did you get a variety of all food types?
Carbohydrates, proteins, fats, water, minerals and vitamins
2.Did your energy input equal your output energy?
9

10. Input and Output
 What do you think happens if:
Energy Input > Energy Output
= Increase in weight
Energy Input < Energy Output
= Decrease in weight
10

11. 
17,58456kj
11

12. 
12

13. Success Criteria
  In order to stay healthy our diets should be what?
 Balance of protein, fats and oils and carbohydrates
 Contain all food types
 What happens if we do not maintain a healthy diet?
 Become obese, lack of energy, brittle bones, diabetes
 Memory loss, malnutrition,
 How can you tell if you have a healthy diet?
 Active, clear eyes, reddish gums, focused, strong pink
fingernails, flexible skin, shiny hair
 How can you tell if you have an unhealthy diet?
 Unfocused, difficulty concentrating, limp hair that
breaks off, brittle fingernails, dull complexion
13

14. SLO

Name the main food groups
and give examples of each
14

15. Dietary Intake
 Sort the pictures provided into
five food groups
 Now put them in order of which
you should eat the most, eat in
small amounts and eat least of.
 Why is it important to eat the
correct amounts of each type of
food group?
15

16. 
16

17. Food Groups
Look at the pictures provided and see if
you can group them, give each group a
name.
Try to figure out what your body uses
each food type for.
17

18. 
18

19. 
 http://e-learningforkids.org/Courses/EN/S0703/launch.html
19

20. Food types
TTyyppee FFoouunndd iinn UUsseess

Carbohydrates
Fats
Proteins
Vitamins
Minerals
Fibre
Water 20

21. Food types
TTyyppee FFoouunndd iinn UUsseess

Carbohydrates
Fats
Proteins
Vitamins
Minerals
Fibre
Water
Bread, potatoes, cereal
Cream, butter, milk, oil
Meat, fish, eggs
Vegetables, cereal
Meat, milk, cereal
Fruit + veg, cereal
Water!
Energy
A store of energy
Building and repairing cells
Keep things “ticking over”
Strong teeth etc
Keeps you regular!
75% of the body is water
21

22. Sort the Food into
Groups

22

23. Flush the Food

23

24. 
 http://lgfl.skoool.co.uk/content/keystage4/biology/pc/modules/24

25. Important Substances
Our bodies require certain other substances in
order to stay healthy:

Iron: used in blood to carry oxygen need for
respiration which makes energy! (green vege,
red meat)
Fibre: keeps intestines clean, helps move the
food through the intestines (cereals)
Calcium: helps strengthen our bones (diary
products)
Water: helps in metabolic process and keep
cells alive
25

26. Important Substances
What types of foods do we get these from?

26

27. Success Criteria

1. Write a definition of the following words: diet,
nutrition
2. List the types of foods which contain lots of the
following
Carbohydrates, proteins, fats, vitamins
3. State what each of the above substances do in the
body.
4. Complete Scipad page 149-150 and 154-155
27

28. SLO

 Gain an understanding of some of
the diseases caused by poor diet
28

29. Dietary Intake

29

30. Modern diets and health problems

% obesity in the UK
30

31. Dietary Problems
Too much or too little of certain things in our diet can
cause major health problems.

Solve Theo’s health
problems.
http://
lgfl.skoool.co.uk/content/keystage3/biology/pc/learni
ngsteps/MALLC/launch.html
31

32. Dietary Problems

Research two of the following dietary problems.
Obesity, Anorexia, Bulimia, Malnutrition, Anemia,
Goiter, bowel cancer, diabetes, heart disease,
dehydration,
You need to find out:
What causes the problem
What effects does the problem cause
How can the problem be cured?
32

33. Dietary Problems

Obesity can result in:
Heart disease
Heart attack
Type II diabetes
Infertility
Lack of fibre can result in:
Constipation
Bowel Cancer
33

34. Tasks
Read and complete the questions on the following
pages in Exploring Science 8
Page 10-11 and Page 12-13

Complete the following worksheets:
The Glycaemic Index 8Ac/7
Balanced Diets 8Ab/8
Poor Diets 8Ab/2
Focus on Diet and Diabetes 8Ab/3
On a diet 8Aa/1
Eat to live 8Ae/6
34

35. Poor diets
If we don’t have a balanced diet we may suffer form a
“deficiency symptom”:

Lack of… Causes…
Vitamin D
Protein
Vitamin C
Vitamin A
Iron
Calcium
Anaemia
Scurvy (bleeding gums and joints)
Weak bones and teeth
Wasting of body tissue
Rickets
Poor night vision
35

36. Success Criteria
Explain what a balanced diet is.
 1. Write a definition of the following words: diet,
nutrition, energy input, energy out put, food
pyramid, calcium, fibre, water,
2. What type of food substance is calcium?
3. Why is fibre important in the diet?
4. What makes up the missing mass in most foods?
5. Complete Scipad page 156
36

37. Success Criteria
Explain what a balanced diet is.

1. Bob has become very overweigh in the last few years.
He used to play a lot of sports and go to the gym
everyday, but he injured his knee and cannot play sports
anymore and he has stopped going to the gym.
 Bob still eats the same about of food as he did before
his knee injury. Suggest two reasons why he might
be overweight now.
 Suggest two health problems the Bob could have as a
result of becoming overweight.
 Suggest two ways in which Bob might lose mass.
37

38. SLO

Carry out a number of food test
investigations
38

39. Food Tests

 http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/FOTLC/launch.html
 Complete scipad pages 151-153
39

40. 
Food type
Tested for
Method Positive Test
Result
Foods that
contain this
Carbohydrate:
Starch
1. Put 1 ml of water in a test tube
2. Add 1 pinch of ground food
3. Add 2 drops of iodine solution
4. Shake it, record colour change
Carbohydrate:
Glucose
1. Put 1 ml of water in a test tube
2. Add 1 pinch of ground food
3. Add 5 drops of Benedict’s solution
4. Shake well, then gently heat
5. Record colour change
Oils 1. Put 1 ml of alcohol into a test tube.
2. Add 1 pinch of the liquefied food.
3. Shake well. Then pour into another
test tube that contains 1ml of water.
4. Shake well, record change in
appearance.
Protein 1. Put 1ml of food into a test tube.
2. Add 1ml of sodium hydroxide.
3. Add 4 drops of copper sulphate
solution.
4. Shake well and record colour
40

41. Food tests 1
To investigate what happens in digestion we need to be able
to test for different foods. Here are two simple tests:

1) The test for starch:
Drop some iodine onto the food. If
the iodine turns BLUE/BLACK then
STARCH is present.
2) The test for simple sugars (e..g
glucose)
Boil the food with some Benedict’s
solution. If an orange
“precipitate” appears then the
food contains simple sugars
Iodine
41

42. Food tests 2
1) The test for protein:
Add 5cm3 of dilute sodium hydroxide

followed by 5cm3 of dilute copper
sulphate. If protein is present it
will produce a purple colour.
2) The test for fats:
Shake the food with about 10cm3 of
ethanol in a test tube. Pour some
of the solution into a tube
containing water. If fat is
present the water will turn
cloudy white.
42

43. Success Criteria

1.Draw a labelled diagram to show how to test
for protein, starch, sugar and fats
2.Give the positive results expected for foods
that contain starch, protein, sugar and fat.
3.Complete Scipad pages 149-154
43

44. SLO

Label the major organs of the
digestive system
Outline the main function of the
digestive organs
44

45. Before

 Draw an outline of a body
 Draw and label the following organs
 List any organs you don’t know on the side of
the poster
Heart, lungs, kidneys , bladder, oesophagus,
trachea, stomach, liver, gall bladder, large
intestine, small intestine, pancreas, appendix,
ureter, urethra, diaphragm, eyes, bile duct,
larynx
45

46. Nutrition

46

47. Nutrition
There are four stages to nutrition (obtaining and
using food for energy):

Ingestion
 Using our teeth and mouths to physically get food into our
body
Digestion
 Chemically breaking down food into smaller particles
Absorption
 Broken down food particles pass from our small intestine into
our blood
Excretion
 Liquid waste is excreted via the kidneys and bladder
 Solid waste is excreted via the anus
47

48. 
48

49. 
49

50. Digestion
What is digestion? 
Turns food into a form that your body
can use
Why do we need to digest food?
Food particles are to large to fit through
cell membranes and be absorbed and
passed around the blood stream
50

51.  Once you have ingested your food with your teeth,
enzymes then digest it.
 Digestion means to break particles. These smaller particles 
down into simpler smaller
can then pass
through the cell membrane of the intestines.
 Digestion first takes place in your mouth where an
enzyme called amylase (found in your saliva) breaks
down starch into smaller particles.
 Digestion is a chemical process that takes place in
the mouth, stomach and small intestine.
51

52. The digestive system
The whole point of digestion is to break down our food so
that we can get the bits we need from it…

The main foods
affected are
CARBOHYDRATES –
these are broken down
into GLUCOSE
52

53. Digestion

1) In the mouth food
is mechanically
broked down by the
teeth and chemically
broken down by
enzymes in saliva
2) In the stomach
food is chemically
broked down by
enzymes and acid is
produced to kill
bacteria and help the
enzymes work
3) In the small
4) intestine In the enzymes
large
intestine 5) complete The waste excess
the
faeces
digestion are water removed is absorbed
process through
and
into glucose the anus
the and blood
other
small foods are
absorbed into the
bloodstream.
53

54. Other facts to digest...

The liver produces bile
to help digest fat
The gall bladder stores
bile before releasing it
into the small intestine
via the bile duct
The pancreas produces
lots of enzymes
54

55. Label the Digestive
System

 http://www.neok12.com/diagram/Digestive-System-
01.htm
 http://nature.ca/discover/exm/blddgstvsystm/index_e.
cfm
 http://www.purposegames.com/game/1918
 http://e-learningforkids.
org/Courses/Liquid_Animation/Body_P
arts/Digestive_System/index.html
55

56. 
56

57. 
57

58. 
58

59. Function of Organs
Mouth – Chemical break down – amylase
- Physical break down – teeth
Gullet/Oesphagus – moves food to stomach
Stomach – stores food and digestion begins
Small intestine – digestion continues and nutrients
are absorbed
Large Intestine – water is absorbed and feaces are
compacted
Anus – wastes are excreted.
59

60. 
60

61. 
61

62. Rat Dissection
 Animated Rat dissection [www.keepvid.com].mp4
 Complete Scipad 157-158,
62

63. Success Criteria
 Draw a flow diagram of the digestive system
 Where is food first acted on Mouth – saliva contains enzyme 
by enzymes?
amylase
 Where are proteins first digested?
Stomach – protease breaks down proteins
 Where are carbohydrates first digested?
Mouth – amylase digests carbohydrates
 What happens to food in the stomach?
Broken down and mixed and bacteria killed
 Why do we need teeth? How do they help with
digestion?
Breaks food into smaller parts so can be swallowed and
so enzymes can act on it quickly
 What else occurs in the mouth that aids digestion?
Chemical breakdown, moistening of food
63

64. 
64

65. SLO

Explain how various structural
adaptations aid digestion
65

66. 
66

67. The small intestine
This is where the “small parts” are absorbed into our blood
stream…

Everything else
passes into the
large intestine
Glucose gets
absorbed into
the blood
67

68. Absorption
Once digested glucose, vitamins, minerals
and fats are absorbed 
through the wall of the
small intestine.
To ensure this happens as fast as possible,
the small intestine is covered in thin hair like
projections called villi.
These increase the surface area so that
substances can be absorbed fast.
http://lgfl.skoool.co.uk/content/keystage3/biology/pc/learningstep
s/EGSLC/launch.html
68

69. Villi
 Villi are only one cell thick so that
substances can move quickly into
the blood in the capillaries.
 The capillaries join up to form
veins which take the blood to the
liver to be cleaned before the heart
pumps the blood around the body
for use.
69

70. Success Criteria
1. Write a definition of the following words:
absorption, surface area, villi, artery, vein, small
intestine, large intestine, villus, capillary,
pressure
2. Where are most substances absorbed into the blood?
3. Where are water and minerals absorbed into the blood?
4. Complete scipad 163-167
70

71. Label Race

 http://www.purposegames.com/game/label-the-hearts-parts-
quiz
 http://www.neok12.com/diagram/Circulatory-System-
01.htm
 http://www.neok12.com/diagram/Digestive-System-
01.htm
 http://www.neok12.com/diagram/Photosynthesis-
01.htm
71

72. SLO

 Outline the structure and
function of teeth
72

73. Teeth

Why do we have teeth?
Teeth are for breaking up food into smaller pieces so
that they can be swallowed or ingested.
There are different shaped teeth for different jobs:
Canine: Sharp and pointy for tearing
Incisors: Chisel like for biting
Molars: Large and flat for chewing
73

74. 
Enamel – protects tooth from wear and
tear
Dentine – supports enamel, has nerves
in
Pulp – has blood vessels to supply
nutrients to tooth, nerves to send
messages to brain
Gum – where root is implanted
74
Function of Teeth

75. Your Teeth

Look at your own teeth
Copy the diagram
Label your incisors I
Label your canines C
Label your molars M
How many teeth do you have in total?
How are you teeth different to your neighbors?
75

76. Teeth and Diet
 Different teeth are used to eat different foods:
Canines – tearing meat
Incisors –cutting grass
Molars – grinding food
Hence, animals with different diets also have different amounts
of each type of tooth.
 A rabbit that eats grass would need i_____ to cut the grass
and m______ to chew it.
A dog would need large c_____ to tear meat from the bone.
76

77. 
Name the different kinds of teeth and give their
function
What kind of teeth do carnivores, omnivores and
herbivores need most of?
77
Success Criteria