Components of Food-Class 6-Science-NCERT solutions
NCERT notes alongwith solutions for class 6 science “Components of Food” are provided here. The notes as well as solutions are very much helpful for the students to understand the topics. The solutions will be handy for quickly completing the homework and preparing for exams.
- Food is a substance which is consumed to obtain energy for growth, functioning and maintenance of good health.
- Food acts like a fuel which provides us energy.
- Food that we eat is usually made up of one or more ingredients. These ingredients contain some components which are generally called nutrients.
What is nutrients?
- Nutrients are the substances that provide energy for growth, functioning and maintenance of our body.
- Carbohydrates, Fats, Proteins, Vitamins and Minerals are the main nutrients found in the food. Besides, food also contains dietary fibre and water that our body needs.
Categorization of nutrients?
- Nutrients are categorized into two groups:
Functions of Food
- It provides energy to perform various activities like walking, talking, running etc.
- It helps in the proper growth and development of our body.
- It helps in repairing damaged or injured cells or organs of our body.
- It protects our body from various diseases and regulates body functions.
Components of food
There are five main components of food.
- Carbohydrates
- Fats
- Proteins
- Vitamins
- Minerals
Besides, our body also requires dietary fibre and water.
Carbohydrates
- Carbohydrates are macronutrients.
- It is made up of carbon, hydrogen and oxygen.
- Carbohydrates are the main source of energy. That is why it is also called energy-giving food.
- Edible sugar, Starch, Cellulose etc. are a few examples of carbohydrates.
Sources of Carbohydrates
- Sucrose – Honey, Sugarcane etc.
- Fructose – Fruits
- Starch – Bread, Wheat, Rice etc.
- Lactose – Milk and Diary Products
Functions of Carbohydrates
It is the primary source of energy for our body.
Fats
- Fats are high energy-giving nutrients.
- It gives us much more energy as compared to the same amount of carbohydrates.
- Food containing fats is also called energy-giving food.
Sources of Fats
- Plant Source – Nuts, Mustard Oil, Sunflower Oil etc.
- Animal Source – Butter, Ghee, Meat etc.
Functions of Fats
- It also provides energy to our body.
- It acts as a protective barrier and helps in preventing injury.
- It insulates our body against cold.
Protein
- Proteins are polypeptide chains made up of amino acids.
- Proteins are often called body-building foods.
- Proteins are needed for the growth and repair of our body.
Sources of Protein
- Plant Source — Beans, pulses, chickpeas etc.
- Animal Source — Fish, eggs, meat etc.
Functions of Protein
- It helps in the proper growth of our body.
- It helps in repairing damaged tissues of our body.
Vitamins
- Vitamins are micronutrients.
- It helps in protecting our body against diseases.
- Vitamins also help in keeping our eyes, bones, teeth and gums healthy.
Types of Vitamins
There are two types of vitamins:
Sources of different types of Vitamins
- Vitamin A – Papaya, Carrot, Mango, Fish, Milk
- Vitamin B – Rice, Wheat, Liver
- Vitamin C – Oranges, Tomato, Green Chili
- Vitamin D – Fish, Egg, Liver
- Vitamin E – Sunflower Oil, Almond, Avocado
- Vitamin K – Spinach, Broccoli, Lettuce
Functions of Vitamins
- It helps in protecting our body against our body.
- It also helps in keeping our eyes, bones, teeth and gums healthy.
Minerals
- Minerals are micronutrients.
- It is required by our body in a small amount.
- Minerals help in the proper growth of the body as well as maintaining health.
- Lack of minerals can result in several health issues and disorders. Calcium, Sodium, Magnesium, Iodine, Phosphorous, Iron etc. are examples of minerals which are required by our body to perform various functions properly.
Sources of Minerals
- Calcium – Milk, Eggs, Cheese etc.
- Sodium – Salt, Milk etc.
- Magnesium – Pumpkin, Chia seeds etc.
- Iodine – Seafoods, Iodised Salt etc.
- Phosphorous – Milk, Cashew nuts etc.
- Iron – Spinach, Apple etc.
Functions of Minerals
- It helps in the proper growth of the body.
- It helps in maintaining good health.
- It helps in making bones and teeth healthy.
Other two components of food
Dietary fibre and water are the two other components of food.
Dietary Fibre
- Dietary Fibres are also known as roughage.
- It is mainly provided by plant products in our foods.
- Dietary Fibres do not provide any nutrients to our body.
- It helps our body get rid of undigested food.
Sources of Dietary Fibre
Plant Source — Whole grains, Pulses, Potatoes etc.
Functions of Dietary Fibre
It helps our body to get rid of undigested food.
Water
- Water helps our body to absorb nutrients from food.
- It also helps in throwing out some wastes from the body in the form of urine and sweat.
- We get most of the water that our body needs from the liquids we drink — such as water, milk, tea, fruit juice etc.
Balanced Diet
A diet which contains all the essential nutrients like carbohydrates, fats, proteins, vitamins and minerals in the proportion required for the normal growth and development of the body is called a balanced diet.
Deficiency Disease
Diseases that occur due to a lack of nutrients over a long period are called deficiency diseases. There are many diseases caused by a lack of carbohydrates, fats, proteins, vitamins and minerals as shown in the table below:
Deficiency Disease due to lack of Carbohydrates
- Marasmus
- Weak body and low energy
Deficiency Disease due to lack of fats
- Weak body
- increase in hair fall
- dry skin
Deficiency Disease due to lack of Proteins
- stunted growth
- swelling of the face
- discolouration of hair
- skin diseases
- diarrhoea
Deficiency Disease due to lack of Vitamins
Deficiency Disease due to lack of minerals
Test for the presence of starch (Carbohydrates) in food
- Starch is a form of Carbohydrate.
- Take a small quantity of food items.
- Put 2-3 drops of dilute iodine solution on it.
- After a few minutes, if the colour of the food item turns blue-black then it indicates that it contains starch.
Test for the presence of protein in food
- Take a small quantity of a food item (grind or mash form) in a clean test tube
- Add 10 drops of water to it and shake the test tube.
- Now add two drops of a solution of copper sulphate and ten drops of solution of caustic soda to the test tube. After a few minutes, if the colour of the food item turns violet then it indicates the presence of proteins in the food item.
Test for the presence of fats in food
- Take a small quantity of a food item.
- Wrap it in a piece of paper and crush it.
- Now, straighten the paper and observe whether any oily patch was found on the piece of paper.
- An oily patch on paper indicates that the food item contains fat.
Solution of the exercise
1. Name the major nutrients in our food
Ans: The major nutrients in our food are:
- carbohydrates
- proteins
- fats
- vitamins
- minerals.
2. Name the following:
(a) The nutrients which mainly give energy to our body. (b) The nutrients that are needed for the growth and maintenance of our body. (c) A vitamin is required for maintaining good eyesight. (d) A mineral that is required for keeping our bones healthy.
Sol:
- The nutrients which mainly give energy to our body – Carbohydrates
- The nutrients that are needed for the growth and maintenance of our body – Proteins
- A vitamin required for maintaining good eyesight – Vitamin A
- A mineral that is required for keeping our bones healthy – Calcium
3. Name two foods each rich in: (a) Fats (b) Starch (c) Dietary fibre (d) Protein
Sol:
(a) Fats – Ghee, Meat
(b) Starch –Rice, Wheat
(c) Dietary fibre – Pulses, Black beans
(d) Protein – Eggs, fish
4. Tick () the statements that are correct.
(a) By eating rice alone, we can fulfill nutritional requirement of our body. ( ) (b) Deficiency diseases can be prevented by eating a balanced diet. ( ) (c) Balanced diet for the body should contain a variety of food items. ( ) (d) Meat alone is sufficient to provide all nutrients to the body. ( )
Sol:
(a) By eating rice alone, we can fulfill nutritional requirement of our body. (wrong )
(b) Deficiency diseases can be prevented by eating a balanced diet. ( correct)
(c) Balanced diet for the body should contain a variety of food items. (correct )
(d) Meat alone is sufficient to provide all nutrients to the body. ( wrong)
5. Fill in the blanks.
(a) ______________ is caused by deficiency of Vitamin D. (b) Deficiency of ______________ causes a disease known as beri-beri. (c) Deficiency of Vitamin C causes a disease known as ______________. (d) Night blindness is caused due to deficiency of ____________ in our food.
Sol:
(a) rickets
(b) vitamin B1
(c) scurvy
(d) vitamin A