How important is protein in our diet?
The word “protein” is derived from the Greek word “proteios”, which means primary or holding first place. The way name suggest this group of components are the most important cell constituent. Protein is present in all cells of the body. It is present in variable level in different tissues of the body like muscles contain about 20% where as in blood plasma it is 7%.
In the body, protein plays an important role in the biochemical, biophysical and physiological processes. Protein is required for almost all functions of the body as well as the structural integrity of the cells. The structural integrity of the cell is maintained by the protein component present in the cell membrane. Protein regulates gene – the basic code of life and is present in enzyme – the catalyst used in different chemical activity in the body and hormone – the substances, that control and stimulate organs. Protein is the major components of the disease producing organisms like virus, protective substance like antibodies and treatment medications like antibiotics.
Proteins are very complex nitrogenous organic compounds built up of smaller units called amino acids. There are about 21 amino acids in the body. Most of the amino acids can be synthesised in the body but few can not be synthesised and to be provided in the food. Since it is essential to be provided in food for normal functioning of the body, they are called essential amino acids. There are eight essential amino acids and they are isoleucine, leucine, lysine, methionine, phenylanine, tryptophan, threonine and valine. In infants apart from these amino acids histidine is essential to be provided in food. It is wrong to think that since non-essential amino acids can be synthesised in the body, their inclusion in the diet has no value. Some non-essential amino acids can be synthesised only from other essential amino acids so if they are not supplied in the diet some of the essential amino acids will have to be used for their synthesis.