Food
Class 6 Science (Biology) Chapter 2
Every organism needs food to get energy, for growth, repair
and maintenance of the body and to fight diseases.
Energy :- The capacity to do work.
·
The baby plant (Embryo) grows by using the food
stored in the seed (Cotyledon or Seed leaves).
Fig of parts of seed
|
Parts of Plant |
Food |
|
Root |
Carrot, Radish, Beetroot, Turnip,
Sweet Potato |
|
Stem |
Sugar Cane, Potato, Colocasia (arbi), Ginger, Onion |
|
Leaf |
Spinach, Cabbage (bud), lettuce,
Fenugreek (Methi) |
|
Flower |
Cauliflower, Broccoli, Moringa (Sainjan), Banana |
|
Fruit |
Banana, Mango, Guava, Papaya,
Brinjal, Tomato, Cucumber |
|
Seed |
Pulses, Peanuts, Almonds, Walnuts, Coconut, Fenugreek |
Poultry :- A place where birds or fowl are kept for meat and eggs.
Apiary :- A place where bees are kept for the production of honey
Apiculture :- Practicing of bee keeping is called
Apiculture.
Trawlers
:- Mechanised
boats use to fish in the area.
Diet :- Diet is the food we generally eat.
Balance Diet :- A diet containing all the nutrients
required by the body in the right proportion.
Obesity :- It is an excess accumulation of fat in our body.
Components of Food
Nutrients (Constituents of food)
Nutrients:- Chemical substances in food which required by
our body is called nutrients.
Carbohydrate
Contains Carbon, hydrogen and Oxygen.
Sugars are the simplest carbohydrates, like glucose
and fructose.
Glucose :- Found in grape juice. Can be broken down
very quickly by the body to release energy.
Fructose :- Found in honey.
Starch :- It is another type of carbohydrates (more
complex than sugar). Formed of many molecules of sugar and also gives more
energy. It is not sweet like sugar and not soluble in water.
Cellulose :- The substance which form the s the cell
walls of plant cells. (Carbohydrate)
Test of starch :- After adding few drops of iodine in
food sample, it will turn blue-black due to presence of starch.
Note :- We get most of our requirement of
carbohydrates from plants. Plants produce carbohydrate during photosynthesis,
and store them in the form of starch, sugar and fats. Fruit juice contain
sugars, while potatoes, rice and tapioca are rich in starch.
Fats
- It is also compound of carbon, oxygen and hydrogen.
- 1 gram fat = 2 gram carbohydrate.
- Fats gives double energy. That’s why the body takes long time than carbohydrate to break down.
- Starch or sugars can’t be stored in our body like fat.
- Access carbohydrate in our body is converted into fat, and stored under skin and around liver and kidneys.
- Fats feel greasy and are insoluble in water.
Taste of fats :- Fats leave a greasy and translucent
spot on paper.
Proteins
- It contains nitrogen, carbon, oxygen and hydrogen.
- They
are needed to make new cells for growth and to replace old cells (or tissues).
- The
main function of proteins is to form tissues.
- Our
hair, nails, skin and muscles (wool and silk) are made up of proteins.
- Proteins
clump together when you heat them.
- Animal
proteins are considered better than proteins as they are more completely
digested.
Vitamins
- Deficiency disease :- The disease caused by the lack of vitamins.
- Vitamins are also manufactured by drug companies for treatment.
- Chemical name have been given to vitamins, they are still referred to as vitamin A, B, C and so on.
- Classification of vitamins :- i) Soluble in water ii) Soluble in fat
- To perform their functions, vitamins should be in solutions.
- Some 20 vitamins have been isolated so far including Vitamin A, B-complex (B1, B2, B6, and B12), Vitamin C, D, E, K
Minerals
Minerals :- Important elements required by our body
is called minerals. Such as Sodium, Potassium, Calcium, Magnesium, Chlorine,
Iron, Fluorine, Sulphur, Phosphorus, and Iodine.
- ·
Common Salt contains Sodium and Chlorine.
- ·
Calcium, Phosphorus help in building strong
bone and teeth.
- ·
Lack of iron causes Anaemia
- ·
Lack of Iodine causes Goitre.
Water
Water accounts for about 70% of the weight of individual.
Functions of water in our body:-
1.
To perform chemical reaction in our body.
2.
To carry digested food around the body.
3.
To carry out waste through our body.
4.
To regulate the body temperature through the
process of sweating.
Excretion, Sweating and breathing makes us about 2-3 litres
of water every day.
Dehydration :- The excess loss of water through a
body called dehydration.
In dehydration, along with water the body loses minerals
like sodium and potassium, which leads to cramps.
ORS (Oral Rehydration Solution) = 4 spoon sugar + 1 spoon salt
+ few drops of lemon.
Roughage
The substance in our diet used as helper in excretion or to
ensure the smooth movement of waste through the rectum is called Fibre or roughage.
Ex.-
Cellulose (the wall of plant
cell)
Whole grain flour,
Whole pulses
Green peas,
Green vegetables and
Fruits
Balanced Diet
Science Notes Class 6
A diet that contains all the nutrients required by the body
in the right proportion is called a balanced diet.
Classification of nutrients :-
Energy-rich
: fats and carbohydrates
Tissue-building
: proteins
Protective
: vitamins and minerals
A diet must have all three types of nutrients.
Lack of Nutrients
- People who do not get enough to eat are generally said to suffer from malnutrition.
- Lack of proteins lead to symptoms like discoloration of hair, distended stomach, swollen ankles and patchy skin.
- Diseases caused by the lack of nutrients are called deficiency
diseases.
- Deformities of the legs are called bow legs and knock knees.
- Deformed chest is called pigeon chest.
Vitamins/Minerals and their deficiency diseases
Vitamin A - Night
blindness
Vitamin B1 - Beriberi
Vitamin B6 - Pellagra
Vitamin B12 - Anaemia
Vitamin C - Scurvy
Vitamin D - Rickets
Iodine - Goitre
Calcium - Weak bones
Phosphorus - Weak bones
and teeth
History Notes Class 6
Fig vitamin and their functions
Components of Food Notes 6, Components of Food notes class 6, Class 6 notes Chapter 2 Bharti Bhawan,
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