01 February 2011


What are Proteins?

Proteins are bio molecules which are formed from amino acids. Proteins are required for the normal functioning of the body. These form the basis of the structure of the body like the skin and hair. Substances like the antibodies and the enzymes are also formed from proteins. These are complex molecules of large size and play a major role in our bodies. Most of the proteins' functions are concentrated in the cells. However, they also play a vital role in the structure, regulation and functions of the tissues and organs of our body.

Chemical Composition of Proteins

Hundreds of smaller units of amino acids join up in long chains to form protein. There are a total of 20 different amino acids, which combine to form a protein structure. It the amino acid sequence which decides how the 3 dimensional structure of a particular protein will look like and what will be its function. The chemistry of proteins also teaches us that out of the 20 amino acids, 12 are synthesized by the body and are grouped under the category of non-essential amino acids. The rest of the amino acids are supplied by the food we take and are grouped under the essential amino acids.

Types of Proteins

Proteins can be categorized into two types - structural proteins and functional proteins:
  • Structural proteins - This type of proteins are found in the bones, muscles, hairs, skin, blood, connective tissue, nails and some other parts of the body.
  • Functional proteins - Functional proteins help in the formation of several hormones as well as regulate their functions. They are also involved in the formation and function of several antibodies and digestive enzymes. The nuclei of cells contain these proteins from where hereditary traits are transmitted.

Role of Proteins

Proteins have several functions to execute. Some of the major functions of proteins are:
  • Proteins form antibodies which bind to specific foreign particles like bacteria and viruses. Example: Immunoglobulin
  • Enzymes which are responsible for carrying out the chemical reactions in the cells are also formed of proteins. The enzymes are also responsible for molecule formation by making use of the DNA genetic information. Example: Phenylalanine hydroxylase
  • There are special types of proteins called Messenger proteins which are responsible for transmitting signals for the coordination of biological processes. Example: Growth hormone
  • Proteins also form support system for the cells and provide them structure. They help in body movement. Example: Actin
  • Proteins also bind to atoms and molecules and carry them to different parts of the body. Example: Ferritin

Sources of Proteins

Some of the good sources of proteins are as follows:
  • Meat
  • Fish and Seafood
  • Eggs
  • Dairy products like Milk, Yogurt and Cheese
  • Pulses
  • Soy
  • Vegetables

High Protein Diet Dangers

If you think a high protein diet comprising of fish, meat and eggs can make you healthy, then consider thinking again. These diets only work when you have eliminated carbohydrates from your diet completely. However, this will result in a condition where there will not be enough fat and the incomplete oxidation will lead to ketosis. Ketosis is a condition where the patient nauseates continuously and suffers from reduced appetite.

Protein Deficiency in India

In developing countries like India Protein deficiency is major issue as it leads to ill health which in a majority of cases results in death. Kwashiorkor is one such dreaded disorder caused by the deficiency of protein and malnutrition. Protein deficiency also results in reduced intelligence and in severe cases mental retardation. The symptoms of Kwashiorkor are diarrhea, stunted growth, apathy, flaky skin, fatty liver, inactivity, and edema. The scenario of protein deficiency in India is very prominent in the rural areas, more so in the northern regions of the country.

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