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Chapter 2 Nutrition

a) Carbohydrates

-To supply energy

b) Protein

-To replace body tissues

-To build new cells-Required for the formation of enzymes, hormones, haemoglobies and antibodies

c) Fats

-Help to keep our body warm-Protects organ like heart and kidney from damage

-Dissolves vitamins A, D, E, and K

d) Vitamins

-To maintain a healthy body and to prevent diseases

(i)Vitamin Ato prevent night-blindness and skin infections

(ii)Vitamin Bto prevent beri-beri and pallegra and anaemia

(iii)Vitamin Cto prevent scurvy (bleeding gums)

(iv)Vitamin Dto prevent rickets and tooth decay(v)Vitamin Eto prevent sterility

(vi)Vitamin Kblood clotting

e) Minerals

Mineral Source Function Deficiency disease

Calcium Cheese, milk, eggs,

green vegetables-Strong bones and

teeth-blood clotting

-Muscle and nerve

activities

-Rickets

-Osteoporosis-Prolonged bleeding

-Muscular cramps

Sodium Table salt, cheese,

meat

-Maintains body

fluid-Proper functioningof nerves

-Muscular cramps

Iron Meat, eggs, greenvegetables

-needed to formraemoglobin in red

blood cell

-Anaemia

Iodine Seafood, iodised salt -Needed to make

hormones of the

thyroid gland

-Goitre (swelling of

the thyroid gland in

the neck

Phosphorus Eggs, meat, milk,

cheese, vegetables

-Strong bones and

teeth

-Muscle contraction-Stores energy

)-Rickets

-Weakness

Potassium Meat, nuts, bananas -Maintains bodyfluid

-Proper functioning

of nerves-Regulations of

heartbeat

-Weak muscle-Paralysis

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f) Water

-To dissolve chemicals in the body- To regulate our body temperature

-To dispose waste substances like urea and salt through urine and sweat

g) Fibre-To prevent constipation

Food Test

Food Tests Results

Starch Put a few drops ofiodine on starchy food A blue black color isformed if the substances

contains starch

Glucose A few drops ofBenedicts solution or

Ehlings solution and the food substances are

heated in a water bath

A brick red precipitate is

form if the food substances

contains glucose

Protein A few ofMillions reagent and the foodsubstances are heated in a water bath

A red precipitate is formedif the food substancescontains protein

Fats Rub the food substances on a filter paper A translucent grease mark

is formed if the foodcontains fat.

Human Digestive System

Organs Mouth Oesophagu

s

Stomach Duodenum Small

Intestine

Secretion Saliva - i)Gastric

juiceii)hydrochlo

ric acid

i)Bile

ii)Pancreatic

juice

-

Enzymes Salivary

amylase

- Protease i)amylase

ii)Protease

iii)Lipase

i)maltose

ii)Protease

iii)Lipase

Actions Starch

Maltose

Peristalsis Protein

Polypeptides-Kills the

bacteria in

the food

-Provides anacidic

mediumsuitable for

the action of

protease

Emulsifies

fat into oildroplets

Starch

maltose

ProteinPolypeptides

Fats

Fatty acid +

glycerol

Maltose

GlucosePolypeptides

amino

acids

Fats FattyAcid +

glycerol

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