The value of the PROTEIN in diet

Protein is a nitrogenous compund made of a number of amino aids linked together.
Proteins are classified into high and low biological value.

Any high biologial value in adequate amount provides the body needs of amino acids.
All animal proteins are high biologial value,exept gelatin.
All plants proteins are of low biological value,exept of soyabeans.
In this case some of the essential amino aids are either missing or of inadequate amount and so annot maintain growth or support life by itself.

Improve biologial value of plant protein:
When dietary proteins are only or largely of plant source it is necessary to take a variety of plant-protein foods every day,so that missing or inadequate essential amino aids of one food can be supplemented by the other foods.
So,they collectively provide the required essential amino acids and can dispense with animal protein foods.

Sources of protein:
Animal foods:
-milk
-eggs
-meat (muscle,poutry,fish,organ meat like liver,kidney,brain).
Plant foods:
-dried beans,peas,lentils-the main sources,the most richest.
-cereals
-nuts.

Functions of proteins:
Proteins are responsible with :
-Formation of cells (proteins are necessary to form protoplasma),building cells (during growth and pregnancy),maintenance of cells,repair of injuried cells.
-Formation of od essential biological compaunds: hormones,enzymes,immunoglobulins.
-Regulation of fluid movement between blood and tissue
-Combustion (proteins provides around 10% of energy requirement).

When the body is not provided with recommended daily protein requirement  result a protein deficiency .Thsi can lead to:
-protein energy malnutrition in infants and young children.
-undergrowth in shoolchildren
-underweight and debility in adults
-impired immune response
-general weakness and early fatigue.

Low-Protein diet is recommended for:
-pathological conditions associated with disturbed protein metabolism and impaired elimination of metabolic produts (ammonia and urea).
-hepatic failure and hepatic coma.
-kidney disease.

High Protein diet is recommanded for:
-severe hypoproteinaemia
-chronic debilitating desease:malignant disease,tuberculosis,chronic infections.
-cases of negative nitrogen balance: severe injuries and burns.