Chapter 3 3.1 classes of food (NOTE)

CHAPTER 3 :
NUTRITION

3.1 CLASSES OF FOOD

NUTRITION

3.1 :ANALYSING CLASSES OF FOOD
3.2: EVALUATING THE IMPORTANCE OF A BALANCE DIET
3.3: UNDERSTANDING THE DIGESTIVE SYSTEM
3.4: UNDERSTANDING THE PROCESS OF ABSORPTION OF

DIGESTED FOOD
3.5 UNDERSTANDING THE REABSORPTION O WATER

AND DEFECATION
3.6 PUT INTO PRACTICE THE HABITS OF HEALTHY EATING

CLASSES OF FOOD

Carbohydrate Fat Mineral Water
Protein
Vitamin Fibre

EFFECTS OF DEFICIENCY FOOD TEST

CARBOHYDRATE

a. Contain carbon, hydrogen, and
oxygen.

b.Function: Supply most of the
energy our body needs.

c. Examples:

sugar, rice, potato,sweet potato
noodle,flour and bread.

PROTEIN

a.Contain carbon, hydrogen,
oxygen, and nitrogen.

b.Needed for growth and repair of
body tissues.

c. Examples: fish,
meat, egg

FAT

a.Contain carbon, hydrogen, and
oxygen.

b.Help to keep us warm and
protect internal organs.

c.Examples: butter, coconut oil,
corn oil, margarine,

VITAMIN

a.Organic compounds needed in
small amounts by our body.

b.Needed for health and growth.

Vitamin Source Function Deficiency
Disease
A Carrot, liver, ◼ For night vision
fish liver oil, ◼ Healthy skin ◼ Night blindness
and green ◼ Skin infections
vegetables
◼Releases energy ◼ Beriberi
B Eggs, milk, from carbohydrates ◼ Anaemia
meat, yeast, ◼ Healthy nervous
and cereals system ◼Scurvy (bleeding
◼ Healthy skin gums)
C Fresh fruits and ◼ Formation of red
vegetables blood cells

◼Healing of
wounds
◼ Resistance to
Diseases

Vitamin Source Function Deficiency
disease
D Made by our ◼Strong bones
◼Rickets (soft bones and
body in sunlight, and teeth dental decay)

also found in

milk, eggs, fish

liver oil

E Vegetable oil, ◼May be needed ◼ Sterility

whole grains, for reproduction

nuts, ◼ Helps to fight
wheatgerm against diseases

K Made in the ◼ Clotting of blood ◼Prolonged

human intestines, bleeding

also found in egg

yolk, green

vegetables

MINERAL

a.Inorganic compounds needed
by our body,

b.Needed for healthy growth and
development.

Mineral Source Function Deficiency
disease
Calcium Cheese, ◼Strong bones and teeth
milk, eggs, ◼ Blood clotting ◼ Rickets
green ◼ Muscle and nerve ◼ Osteoporosis
vegetables activities ◼ Prolonged
bleeding
◼ Muscular cramps

Sodium Table salt, ◼Maintains body ◼ Muscular cramps
cheese, fluid
meat
◼Proper functioning
of nerves

Iron Meat, eggs, ◼Needed to form ◼ Anaemia
Iodine green haemoglobin in red blood
vegetables cells ◼Goitre (swelling of
the thyroid gland in
Seafood, ◼Needed to make the neck)
iodised salt harmones of the thyroid
gland

Mineral Source Function Deficiency disease
Phosphorus ◼ Rickets
Eggs, meat, milk, ◼Strong bones ◼ Weakness
cheese, vegetables and teeth

◼ Muscle
contraction

◼Stores
energy

Potassium Meat, nuts, ◼Maintains ◼ Weak muscles
bananas body fluid ◼ Paralysis

◼Proper
functioning of
nerves

◼Regulation of
heartbeat

FIBRE

a.Made up of cellulose
b.Prevent constipation
c.Sources of food: green vegetables,

oat, and fruits.

WATER

a. Solvent for many substances in
the body

a. Regulate body temperature

DISEASE: GOITRE EFFECTS OF DEFICIENCY
CAUSES: LACK OF IODINE

EFFECTS OF DEFICIENCY

DISEASE: KWASIORKOR
CAUSES: LACK OF PROTEIN

EFFECTS OF DEFICIENCY

DISEASE: BERIBERI
CAUSES: LACK OF VITAMIN B

EFFECTS OF DEFICIENCY

DISEASE: RICKET
CAUSES: LACK OF VITAMIN D, CALCIUM OR PROTEIN

EFFECTS OF DEFICIENCY

DISEASE: SCURVY (BLEEDING GUMS)
CAUSES: LACK OF VITAMIN C

Iodine test for starch Benedict’s test for glucose

FOOD TEST

Alcohol-emulsion test for fat Millon’s test for protein

Iodine test for starch

Instruction

1. Pour 2 ml of starch suspension into a
test tube.

2.Add two drops of iodine solution into Observation:

the test tube

(Figure 3.3). The solution becomes blue-black.

3. Record your observations. Starch is present.

BACK

Benedict’s test for glucose Observation:

Instruction The brick-red precipitated is
formed.
1. Pour 2 ml of glucose solution into a test tube. Glucose is present

2.Add 2 ml of Benedict's solution into the test tube
and shake it to mix the solutions.

3. Heat the test tube in a water bath for 5 minutes
(Figure 3.4).

4. Record your observations.

BACK

Millon’s test for protein Observation:

Instruction The red precipitated is formed.
Protein is present.
1. Pour 5 ml of albumen suspension into
a test tube. BACK

2.Add two to three drops of Millon's reagent
into the test tube (Figure 3.5 (a)).Then,
shake the test tube to mix the solutions.

3. Heat the test tube in a water bath for 5
minutes (Figure 3.5 (b)).

4. Record your observations.

Alcohol-emulsion test for fat

Instruction

1. Pour 3 ml of ethanol into a test tube.

2.Add 2 to 3 drops of cooking oil into the test tube \

(Figure 3.6 (a)).Then, close the test tube with a stopper.

3. Shake the test tube slowly and leave it in a test tube rack for 2 to 3 minutes. Observation:

4. Place 4 to 5 drops of the mixture from the test tube into another test tube The emulsion layer is
filled with 20 ml of distilled water (Figure 3.6 (b)). formed.

5. Close the test tube with the stopper and shake slowly. Leave the test tube
in the test tube rack for 2 to 3 minutes.

6. Record your observations. Fat is present.

BACK