Protein is a nutrient which is required for proper growth, maintenance and repairing of tissues. It is essential for life because vital parts of the nucleus and protoplasm of every cell are protein. It is present in our skin, muscles, skeleton and in the body fluids.
Proteins are complex organic compounds which contains carbon, hydrogen, oxygen, nitrogen, sulpher and phosphorus.
Our body has the ability to digest only a limited amount of protein. So, if a man takes too much of proteins,he may suffer from indigestion. Our body cannot store excess protein. The body utilizes what it needs and the excess protein is excreted by kidneys.
Though everybody requires protein, yet it is more essential for growing child, pregnant women and mother of milk-sucking child. The man who does hard physical and mental work, also requires protein regularly.
Proteins form new cells and tissues in our body. They repair the damaged cells and tissues of our body. They protect us from diseases and help us in the physical and mental development.
Sources of protein
There are two types of proteins:
i) Animal protein
ii) Vegetable protein
Animal protein is obtained from egg,milk,milk products,meat,fish,liver,cheese,etc. Vegetable protein is found in pulses,cereals, beans, oil seed, gram, green leafy vegetable, legumes,etc.
One gram of protein yields 4.1 calories of heat energy.
Deficiency of proteins
1.Retardation in the growth of children
2. Loss in weight of the body of children.
3. Reduction in the resistance to infection.
4. Pealing of skin, cracks in the skin and causes anemia.
5. Causes Kwashiorkor and Marasmus in children.
6. Lack of protein in the food of children for a long time may cause fatal end of their life.
A child suffering from Kwashiorkor has smaller stomach, swollen limbs, stiff hair and he becomes unable to digest food.
Lack of both protein and calories causes a disease in the children which is called “Marasmus” . A child suffering from this disease has shrunken body, emaciated body, loss of appetite, loss of weight, thin limbs but swollen stomach.