Importance and Functions of Proteins

Proteins are major component of our body cell and play various important roles. Major functions of proteins are detailed out below:

a) Tissue building (growth) and maintenance: This is the main function of dietary proteins. Many proteins are involved in body tissue formation. For example, proteins myosin and actin contribute significantly to muscle structure. Collagen and keratin are other structural proteins.

b) Physiological role: Proteins play a vital role in functionary of body. Enzymes being biocatalyst in nature, are among the most important proteins in the body. They act as catalyst and increase the rate of chemical reactions in the body. Various hormones are of proteinous nature and similar to enzymes regulate metabolic reactions. Besides this, the breakdown product of protein i.e., amino acids, di-peptides, polypeptides are utilized for synthesis of much needed bio-compounds inside body. Tryptophan, an essential amino acid is used to build Niacin (Vitamin B,) and serotonin acts as neurotransmitter. Acid-base balance is important for all physiological activities and is maintained by the buffering action of the proteins. The pH of the blood is slightly alkaline (pH 7.3-7.4). A drastic alteration in blood pH would be fatal. The blood pH is maintained by the buffering actions of proteins, which can accepted release H'essential for pH maintenance. Besides this, blood pigment haemoglobin that helps in transport of gases posses a protein globulin portion. Several lipoproteins are also engaged in transportation work. Protein provides defense to body in the form of antibodies. These proteinous substances are also responsible for gene regulatory, detoxicating and hemostatic function in body. 

c) Energy source: Body does not use proteins as main source of energy. Protein rich foods are expensive. However, proteins can be used for energy requirements ddrhg fasting, long distance running but not in fed state. Protein is also utilized as reserve material for nutrition of developing cells. One gram of protein, releases 4.08 Kcal of energy. It is estimated that close to 58 per cent of dietaty protein may be used up for energy production.