There are twenty-two amino acids, eight of these are considered essential amino acids because they need to be consumed in a diet and are not produced in sufficient quanities by the body. The eight essential amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine. Amino acids are pieces of proteins, amino acids can have endless combinations to form proteins of any kinds. As a result amino acids are aquired through proteins in a diet. Five of these amino acids are considered semi-essential because people low in age or health can not produce these amino acids in their bodies. The semi-essential amino acids are arginine, cysteine, histidine, taurine, and tyrosine. If age and health are optimal these semi-essential amino acids become non-essential amino acids which are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, proline, selenocysteine, serine, tyrosine, and taurine. Taurine is not considered a amino acid, it's non-standard amino acid. Taurine however is a semi-essential amino acid in children but is still not in the amino acid family. Non-essential amino acid are nutrients that the human body can produce enough of on its own with no help from diet. Most amino acids are aquired through eating meat or other protein rich sources. Some animal organs are excellent sources of amino acids. Vegetarians or vegans might need to supplement their diet with amino acids as they do not eat animals or animal related products. Ironically the amino acid supplements come from animals this is because animals and humans are the only sources of amino acids. Amino acids are the basic structure of muscles and other organs. Amino acids compounds that form chains, these chains link with one another forming proteins. Different amino acid chains can be put in almost any combination forming endless types of proteins like the protein found in muscles or the protein found in liver. They are all different types of proteins made up of different types of amino acid chains. Although not all amino acids are strictly animal based. The asparagine amino acid was the first amino acid ever discovered. Two french chemists Louis-Nicolas Vauquelin and Pierre Jean Robiquet in 1806 found asparagine in a asparagus which lead to its name.Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Proline, Pyrrolysine, Selenocysteine, Serine, Taurine Threonine, Tryptophan, Tyrosine, Valine. More infomation on a specific amino acid can be found in the alphabetical list of supplements under amino acids.