Sources of Food, Components of Food, Fibre to Fabric

LESSON – 2

                                                COMPONENTS OF FOOD

Learning Objectives:

v    Able to classify foods according to food components.

v    To analyze the tests for starch, proteins and fats.

v    Able to create a balanced diet.

v    To identify different deficiency diseases and the cause of those diseases.

Answer the following:

1.            Define the following terms:

(a)   Nutrients

           Ans:   Nutrients are the substances that an organism needs for growth, repair and maintenance of its body. The nutrients needed by the human body are carbohydrates, fats, proteins, vitamins and minerals.

(b)   Balanced diet

Ans:  The diet that contains adequate amount of all essential nutrients, roughage and water for the proper growth and development of the body is called a balanced diet.

(c)    Deficiency Diseases

Ans:   Diseases that are caused due to the lack of carbohydrates, fats, proteins, minerals or vitamins in our diet are called deficiency diseases.

2.            How will you test the presence of starch in a given food sample?

Ans:   Take a small piece of the food material and add a few drops of diluted iodine solution using a dropper. If the food sample contains starch, it will turn blue-black.

3.            What is roughage? Why is it important to include roughage in our diet?

Ans:   The fibrous undigestable material present in our food is called as roughage. Roughage helps our body to get rid of undigested food and thereby prevents constipation. Also it can absorb a great amount of water and helps to retain water in the body.

4.            Give two cooking practices that lead to the loss of nutrients in food materials.

Ans:  (1) If cooking is done in excess of water and the water is thrown away after cooking, many water-soluble vitamins and minerals are lost.

          (2) If cooking is done at a high temperature, many proteins and vitamins are destroyed.

5.            Name three deficiency diseases and also write their causes and symptoms.

Deficiency diseases	Causes	Symptoms
1.      Night blindness	Due to lack of vitamin A	Poor vision and loss of vision in darkness.
2.      Beriberi	Due to lack of vitamin B	Feels extremely weak, Swelling of legs, Loss of appetite and weight.
3.      Scurvy	Due to lack of vitamin C	Spongy and bleeding gums.

6.            What is obesity?  What are its causes?

Ans:  The overeating of fat rich foods will lead to an overweight condition called obesity. An obese person suffers from heart-related problems. Many people especially children, eat a lot of junk food such as burgers, chips and soft drinks. All these food items contain large amounts of fats and sugars. Due to lack of physical activity, fats get accumulated in the body and cause obesity.

Activities:

1.      Collect pictures of children suffering from the following deficiency diseases and write its causes, symptoms and prevention of those diseases.

(a)   Kwashiorkor   (b) Marasmus       (c) Nightblindness     (d) Scurvy   (d) Rickets

2.      Make a list of any three junk foods, write their ingredients and the harmful effects of their excessive intake.

New Terms:

1.      Nutrients

2.      Carbohydrates

3.      Roughage

4.      Deficiency diseases

5.      Kwashiorkor

6.      Marasmus

7.      Obesity

8.      Goitre

9.      Anaemia

10.  Balanced diet

                           Lesson- 3                    FIBRE TO FABRIC

Learning Objectives:

Ø  To identify different types of fibres and their uses.

Ø  To analyze the ways by which fabrics are made from fibres.

Answer the following:

1.      What is meant by yarn?

The loose thread in a fabric is called yarn.

2.      Differentiate between natural fibres and synthetic fibres.

The fibres obtained from plants and animals are called natural fibres. Eg: Cotton, silk

Fibres that are made by man from different chemicals in the industries are called man-made or synthetic fibres. Eg: Nylon, Polyester

3.      Write any two uses of jute fabrics.

1  .      Jute yarn is used for making gunny bags or sacks and for wrapping packages.

2  .      High quality jute fibres are woven into curtains, carpets, chair coverings and packing for linoleum.

4.      List the steps involved in the preparation of fabrics.

The following steps are involved in the preparation of fabrics:

(i)        Obtaining fibre.

(ii)      Preparation of yarn from fibres by spinning.

(iii)    When two sets of yarn are involved, yarns are woven on looms to make a fabric. When a single yarn is used, the fabric is prepared by knitting.

5.      What is meant by ginning?

The process of separating seeds from the cotton fibres is called ginning of cotton. It is done by hand or machine.

6.      How is weaving different from knitting?

The process of arranging two sets of yarns together to make a fabric is called weaving.

Knitting is a process of making fabric in which only a single yarn is used.

7.      Explain the method of making yarn from fibre.

The process of making yarn from fibre is called spinning. In this process, fibre from a mass of cotton are drawn and twisted. This brings the fibres together to form a yarn. The simple devices used for spinning are hand spindle and charkha. On a large scale, spinning is done with the help of spinning machines.

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Activity:

1.      With the help of pictures explain the process of making cotton fabric from cotton fibre.

2.      Do weaving process using colour papers and place it in your activity file.

New terms:

1.      Fabric 2.      Synthetic fibres 3.      Knitting 4.      Spinning 5.      Weaving

6.          Ginning 7.           Powerlooms 8.           Roller gin 9.           Polyester 10.       Terrysilk

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