|3D model (Jmol)||Interactive image|
|Molar mass||146.15 g·mol−1|
|Melting point||decomposes around 185°C|
|Acidity (pKa)||2.2 (carboxyl), 9.1 (amino)|
Chiral rotation ([α]D)
|+6.5º (H2O, c = 2)|
|Supplementary data page|
|Refractive index (n),
Dielectric constant (εr), etc.
|UV, IR, NMR, MS|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Glutamine (abbreviated as Gln or Q; encoded by the codons CAA and CAG) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain amide which replaces the side chain hydroxyl of glutamic acid with an amine functional group, classifying it as a charge neutral, polar (at physiological pH) amino acid. It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases and glutamine must be obtained from the diet.
Glutamine plays a role in a variety of biochemical functions:
- Protein synthesis, as any other of the 20 proteinogenic amino acids
- Lipid synthesis, especially by cancer cells.
- Regulation of acid-base balance in the kidney by producing ammonium
- Cellular energy, as a source, next to glucose
- Nitrogen donation for many anabolic processes, including the synthesis of purines
- Carbon donation, as a source, refilling the citric acid cycle
- Nontoxic transporter of ammonia in the blood circulation
- Precursor to the neurotransmitter glutamate
Producing and consuming organs
Glutamine is synthesized by the enzyme glutamine synthetase from glutamate and ammonia. The most relevant glutamine-producing tissue is the muscle mass, accounting for about 90% of all glutamine synthesized. Glutamine is also released, in small amounts, by the lung and the brain. Although the liver is capable of relevant glutamine synthesis, its role in glutamine metabolism is more regulatory than producing, since the liver takes up large amounts of glutamine derived from the gut.
Occurrences in nature
Glutamine is the most abundant naturally occurring, nonessential amino acid in the human body, and one of the few amino acids that can directly cross the blood–brain barrier. In the body, it is found circulating in the blood, as well as stored in the skeletal muscles. It becomes conditionally essential (requiring intake from food or supplements) in states of illness or injury.[medical citation needed]
Glutamine supplementation was thought to have potential to reduce complications in people who are critically ill or who have had abdominal surgery but this was based on poor quality clinical trials; a large randomized clinical trial found worse outcomes in the group that was given glutatmine.
Supplementation does not appear to have an effect in infants with significant problems of the stomach or intestines.
Several brands of glutamine are marketed as medical food and is prescribed when a medical professional believes a person in their care needs supplementary glutamine due to loss or deficiency of glutamine.
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