General Information
Glycine is the smallest and simplest amino acid. It is a proteinogenic amino acid, meaning that it is used in living organisms as an important building block for proteins and is very relevant for a body’s metabolism. Glycine is a particularly common component of the protein collagen. In addition, the amino acid is used, among other things, for the synthesis of DNA components, haem (oxygen binding in the blood) and creatine (energy storage in muscles). As a neurotransmitter in the brain, glycine also plays a prominent role in the nervous system.
The amino acid is largely absorbed through food, but can be synthesised by the human organism itself.
Glycine is not only a component of the body, the substance was also collected by the Stardust space probe in 2004 and detected for the first time in 2009 in particle samples from the coma of a comet.
Chemically, glycine is produced from monochloroacetic acid and ammonia. Another way to produce glycine is the so-called "Strecker synthesis": the reaction of formaldehyde, hydrogen cyanide and ammonia produces aminonitrile, which in turn produces glycine during hydrolysis.
Properties of glycine
Glycine is a colourless and odourless crystalline solid. The substance belongs to the group of hydrophilic amino acids, i.e. it reacts with and is highly soluble in water. In contrast, glycine dissolves poorly in alcohol. The amino acid decomposes at 290 °C and above.
The name glycine is derived from the Greek term for the German word "süß" (sweet) and describes the taste of the substance.
Glycine - like all amino acids - belongs to the ampholytes: it reacts both as an acid and as a base, i.e. it can emit or take up protons. The proton of the COOH group has the ability to migrate to the nitrogen atom of the amino group, creating a so-called "hermaphrodite ion".