An organic compound that contains one or more amino groups and one or more acidic carboxyl groups. Amino acids can be polymerized to form peptides and proteins. Only 20 amino acids occur in living things.
Amino acids are the primary building block of life, and the structural building units of protein when chained together with peptide bonds. Chemically, it's a molecule containing amino and carboxylic acid groups. Most amino acids discussed in biology are alpha amino acids. When a peptide bond is created, a molecule that makes up water is lost from the amino acid.
Several important amino acids include Phenylalanine, proline, glycine, glutamate, and tryptophan. Without amino acids, cells could not function.
In humans, certain amino acids are called essential amino acids; they can't be synthesized by the human body but instead must be ingested with food. Essential amino acids are lysine, histidine, tryptophan, phenylalanine, and several others. Inability to properly synthesize these proteins when they're in the body results in a variety of different medical conditions, most of which lead to death.
Proteins put together with amino acids do a wide variety of essential tasks in the human body, from muscle building to energy synthesis to the creation of histamines and other immune system pieces.
Web Resources On Amino Acid
Wikipedia: Amino Acid
Amino Acid Structures
Book Resources On Amino Acid
Amino Acid and Peptide Synthesis by John Jones
Amino Acids and Peptides by G. C. Barrett