Summary + MCQS – Class 6 Science Chapter 2 (Components of Food)

Food is a basic requirement for all living organisms. It provides energy for carrying out normal physiological activities. There are different components and they have different nutrients. They all come together to provide wholesome nourishment to us. 

For Example:

• Dal, eggs, meat etc contain proteins.
• Fruits and vegetables contain vitamins.
• Cereals, pulses, Oats contain predominantly carbohydrates.
• Oil, ghee, butter, cheese, pork, chocolates, lard and cream contains fat.

What Do Various Nutrients Do for Our Body?

Carbohydrates

Carbohydrates are present mostly as starch. They provide us with energy and are thus energy giving food.
Ex: Wheat, Potato, Rice etc. are good sources of carbohydrates.

Iodine Test for Carbohydrates

Carbohydrates present in all food item are tested by Iodine test. Few drops of dilute iodine solution are added to the sample food item. If the colour changes from brown to blue-black, the presence of starch is confirmed.

Proteins

Proteins are the bodybuilding nutrients. They are needed to build every single part and organ of the body. They help in the growth and repair of our body.

Eggs, Meat, Lentils etc are good sources of proteins.

Test for Proteins

Proteins in the food sample are tested by copper sulfate and caustic soda solutions. The sample food item is made into very dilute paste and the above solutions are added to it. If the colour of the resulting solution changes to purple, the presence of protein is confirmed.

Fats

Fats are high energy nutrients. They are needed in a moderate amount by the body. Fats are the reserved food material of our body.

Oils, ghee, butter etc are the sources of fat.

Test for Fats

Fats in the food are tested by a simple paper test. A little amount of sample food is wrapped in a paper and crushed. If the paper gets an oily patch, the presence of fat in the food is confirmed.

Fibre

• Fibres are materials that add bulk to the food.
• Humans cannot use fibres as a nutrient.
• But they help in the easy movement of the food along with the digestive system.

Balanced Diet

A balanced diet is a diet that has all the necessary nutrients in the amount that is needed for normal body functioning.

Deficiency Diseases

• Deficiency diseases are caused by the lack of certain nutrients.
• These diseases can be treated by a properly balanced diet.
• If the body is deficient in vitamin we get vitamin deficiency diseases.
• E.g. scurvy, pellagra, Rickets etc.
• If minerals are deficient, then we get mineral deficiency diseases.
• E.g. iron deficiency leads to anemia, phosphorus deficiency leads to weak bones and teeth.

Food Sources

Vitamins

• Vitamins are the essential nutrients that help us in maintaining normal body functions and also to fight off infections.
• Fruits and vegetables are the major sources of vitamins.
• Vitamins also keep our eyes, bones, teeth, gums and skin healthy.
• A, B complex, C, D, E and K are the vitamins we get from different foods.

Minerals

• Minerals are important substances that help your body’s form and function on many different levels.
• Minerals are essential for various metabolic functions including growth and organ functioning.
• Important minerals required for our body are sodium, potassium, calcium, zinc, iron, phosphorus, magnesium etc.

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