Amino acids are the building blocks of proteins, which carry out many functions in organismic life.
Some proteins act as catalysts, others serve for storage and transport, while still others are antibodies for our immune system. There are also numerous other functions that different proteins execute. The point is, amino acids are absolutely essential to cellular life. Chemically speaking, amino acids are carboxylic acids which have an amine group attached to it. There are more than 500 amino acids which occur in nature, but only 20 are used in all biological life known on earth.