In 1838, a Dutch chemist, G.J. Mulder, described a certain organic material as "unqestionably the most important of all known substances in the organic kingdom. Without it, no life appears possible on our planet. Through its means the chief phenomena of life are produced. " This complex nitrogen-bearing substance was called protein from the Greek word meaning " take the first place." Protein in now a group name signifying the principal nitrogenous constituents of the protoplasm of all plant and animal tissues.

Proteins are extremely complex organic compounds of the elements carbon, hydrogen, oxygen, nitrogen, and,with some exceptions, sulphur. Most proteins also contain phosphorous, and some specialised proteins contain iron, iodine, copper and other inorganic elements. The presence of nitrogen distinguishes proteins from carbohydrates and fats.

Proteins are thus vital substances, which form important constituent of muscles, tissues, and the blood. Proteins supply the building material for the body and make good the wear and tear of tissues. Several substances concerned with vital life processes such as enzymes, which help in digestion of food, are chiefly protein in nature.

There are several varieties of protein. Each type contains a specific number of "building blocks " known as amino-acids. Before they can be absorbed by the body, all proteins must first be broken down into amino-acids. When food stuffs are ingested, the nutrients and amino-acids do not immediately diffuse into all the different tissues. There are a series of biochemical reactions in the digestive tract which collect these proteins, break them down and then utilise them as needed. Any interference with the normal digestive process causes in-complete protein digestion resulting in gas, bloating etc.

There are about 22 amino acids needed for the normal functioning of the body. The body can manufacture many amino acids if it has no adequate nitrogen source, but it cannot produce certain others in sufficient amounts to meet its needs. The amino acids that the body cannot synthesis is in adequate amounts are called essential or indispensable because they must be supplied by the diet in proper proportions and amounts to meet the requirements for maintenance of growth of the Non-essential or dispensable amino acids are those thatissue. the body can synthesize in sufficient amounts to meet its needs if the total amount of nitrogen supplied by protein is adequate.

Protein is needed by every living organism, and next to water, makes up the largest portion of our body weight since it is contained in muscles, organs, hair, etc. The protein used in making up the body is not directly derived from diet, but the dietary protein is broken down into amino acids, and the body then re-constitute these amino acids into the specific proteins needed.

Enzymes and hormones regulating body functions are also proteins. And amino acids are used in most body processes from regulating the way the body works to how the brain functions - They activate and utilize vitamins and other nutrients.

Proteins are chains of amino acids linked together, bound together with peptide bonds and there are about 28 amino acids commonly referred to in human health.

The liver manufactures about 80% of these amino acids, but the remaining 20% of such amino acids must be supplied directly by diet, and these amino acids are referred to as the essential amino acids.

These essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

The 80% or so others that are manufactured by the liver includes: alanine, arginine, asparagine, aspartic acid, citrulline, cysteine, cystine, gamma-aminobutyric acid, glutamic acid, glutamine, glycine, ornithine, proline, serine, taurine and tyrosine.

The functioning of amino acids are interrelated, and a balanced and steady supply of these nutrients are needed to maintain proper body functioning. A dietary shortage of amino acids can impact negatively on your health - just as other stressors, such as trauma, drug use, age, infections etc.

When the body synthesizes protein, ammonia is formed in the liver as a waste product, and too large amounts of protein into the diet can result in too much ammonia being formed, and in so doing placing extra stress on the liver and kidneys to flush it out the body.

Amino acid supplements come in various forms but can essentially be divided in three types of products - either derived from animal protein, yeast or vegetable protein. Most amino acids can be produced in two forms, except for glycine, that is either a D or L form.

These letters stands for the way in which the amino acid spiral is wound up - D is for the right wound type and L for the mirror left winding amino acid.

Human amino acid is the L type and for this reason many people prefer to use supplements containing the L type amino acid.