Proteins| Nutrients of Food

Proteins| Nutrients of Food

Nutrients of Food

When food splits up different types of bio-chemical ingredients are found. These ingredients keep us healthy and active by performing various functions in our body. They are called nutrients. We use these nutrients for our different purposes. Nutrients are of six types. These are-

(1) Proteins,
(2) Carbohydrates,
(3) Fats,
(4) Vitamins,
(5) Minerals
(6) Water

So we can say that we can have six types of nutrients from our foods. These nutrients are very necessary for building up our body, guarding it and producing heat. These six nutrients perform more than one fttnction in our body. We shall now discuss about Proteins nutrients here.

Proteins

The word 'Protein' is derived from the Greek word 'Proteos' meaning 'to take the first place'. Proteins play a significant role in all activities of living organisms. We cannot even imagine a living being without proteins. They are essential for both animals and plants. For this reason protein is considered as main element of food.

Formation of Protein Or What are Proteins?

Proteins are complex organic compounds which contain carbon, hydrogen, oxygen and nitrogen. Certain proteins contain sulphur, phosphorus, iron, iodine, copper and other inorganic elements. On hydrolysis protein first gives out smaller units called amino acids and then carbon, hydrogen and other basic elements.

What are Amino Acids?

On hydrolysis large molecules of protein give out smaller units of amino acids. Amino acids contain a carboxyl group (-CooH) and an amino group (-NH2). They are thus known as the amino acids. Amino acids are of two types:

a)Essential amino acids
b)Non-essential amino acids

Amino Acids

a.Essential Amino Acids:

Some of the amino acids are not produced in our body and we must meet their requirements through our food. These amino acids are known as essential amino acids.

b.Non-essential Amino Acids:

Some amino acids are manufactured in our body from available chemicals. So we do not have to meet their requirements through our food. These amino acids termed as Non- essential amino acids.

Classification of Proteins

a.On the basis of sources: Proteins are divided into two groups. These are:
1. Animal Protein:

Proteins which we get from animal sources are termed as animal protein, e.g. fish protein, meat protein, egg protein, etc.

2. Vegetable Protein:
Vegetables are the sources of this Kind of protein. Nuts, soybean, etc. are some of its sounes.

b.On the basis of presence of essential amino acids:

Proteins are classified into three groups based on the presence of essential amino acids in them. These are:
1.Complete Proteins:
A complete protein food contains all essential   acids in proper proportion to promote gowth, maintenance and repair. Examples of complete protein foods are milk, egg and fish.

2.Partially Incomplete Proteins:

Partially incomplete proteins lack some  essential amino acids and so they help to maintain our body but yowth is not promoted. Vegetable proteins such as rice, pulse, flour, nut,  etc. are examples of this group. Lentil lacks methionine, rice lacks in lysine, etc.

3.Incomplete Proteins:

Incomplete proteins lack all the essential amino acids, Thus they neither help maintenance nor growth, Zein of maize is an example of this type of protein.

Sources of proteins

Animal proteins:
fish, meat, egg, milk. cheese, posset, etc.

Vegetable proteins:
lentil, soybean, nuts, rice, wheat. etc.
Protein foods

Source of Proteins

Functions of Proteins:

1.Build body and help to grow:

The most important function of protein is to build up our cells and help us to grow. Muscles and other tissues, bones, cartilage, hair, nails and skin contain fairly high percentage of protein.

2.Replete decays: Every moment our old cells are dying and new cells are formed. Protein builds up new cells and replenishes the decay of cells. Protein also heals our wound.

3.Produce heat: Proteins produce heat when our body meets the scarcity of fats and carbohydrates. lgm of protein can produce 4 kcal of energy.

4.Give immune power against diseases: Different types of external organisms enter our body and become the cause of diseases. Proteins produce antibodies which fight against these organisms and give us preventive power against diseases.

5.Develop mental ability: Protein is necessary for mental growth. Mental power or the development of brain retards if necessary protein is not available during the development period.

6.Control internal functions: Enzymes and hormones are made up of proteins and they play vital roles in regulating the internal frnctions of our body.

7.Transport important elements in our body: Hemoglobin, a blood protein, caries atmospheric oxygen to different parts of our body.

8.Regulate water balance: Plasma is another kind of blood proteins that regulates water balance in our body.

Symptoms of Protein Deficiency:

In Children

Children face various symptoms due to deficiency of proteins. Some of them are as follows:
•Retarded growth of body

•Weight loss

•Cracks in the skin
 • Discoloration of hair

•Mental irritation

•Mental retardation

•Reduced secretions of enzymes Indigestion

•Reduced resistance to infection.

These symptoms are found in the pre-kwashiorkor state.

A Marasmus Affected Child

A Kwashior Affected Child

If these conditions persist for long symptoms such as swelling of face, hands and feet occur and this condition is known as kwashiorkor. Children aged between 1 to 4 are mostly affected by this disease condition.

Marasmus occurs when the diet is low in both protein and calories. The body looks shrunken. The child has an emaciated look and wasting of muscles occurs.

In Adults 


Adult face various symptoms due to deficiency of proteins. Some of them are as follows:

•Ascites of hands and feet

• Anemia

•Reduced prevention power against diseases.

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