D-serine

Serine

Names
IUPAC name Serine
Other names 2-Amino-3-hydroxypropanoic acid
Identifiers
CAS Number	56-45-1 (L-) Y 302-84-1 (DL-) Y 312-84-5 (D-) Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:17115 Y
ChEMBL	ChEMBL11298 Y
ChemSpider	5736 (L-form) Y 597 Y
DrugBank	DB00133 Y
ECHA InfoCard	100.000.250
EC Number	206-130-6
IUPHAR/BPS	726
PubChem	617
UNII	452VLY9402 (L-) Y 00PAR1C66F (DL-) Y 1K77H2Z9B1 (D-) Y
InChI InChI=1S/C3H7NO3/c4-2(1-5)3(6)7/h2,5H,1,4H2,(H,6,7)/t2-/m0/s1 Y Key: MTCFGRXMJLQNBG-REOHCLBHSA-N Y InChI=1/C3H7NO3/c4-2(1-5)3(6)7/h2,5H,1,4H2,(H,6,7)
SMILES C([C@@H](C(=O)O)N)O
Properties
Chemical formula	C3H7NO3
Molar mass	105.09 g·mol−1
Appearance	white crystals or powder
Density	1.603 g/cm3 (22 °C)
Melting point	246 °C (475 °F; 519 K) decomposes
Solubility in water	soluble
Acidity (pKa)	2.21 (carboxyl), 9.15 (amino)
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Serine (abbreviated as Ser or S) encoded by the codons UCU, UCC, UCA, UCG, AGU and AGC is an ɑ-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH+
3 form under biological conditions), a carboxyl group (which is in the deprotonated –COO−
form in physiological conditions), and a side chain consisting of a hydroxymethyl group (see hydroxyl), classifying it as a polar amino acid. It can be synthesized in the human body under normal physiological circumstances, making it a nonessential amino acid.

This compound is one of the naturally occurring proteinogenic amino acids. Only the L-stereoisomer appears naturally in proteins. It is not essential to the human diet, since it is synthesized in the body from other metabolites, including glycine. Serine was first obtained from silk protein, a particularly rich source, in 1865. Its name is derived from the Latin for silk, sericum. Serine's structure was established in 1902.

The biosynthesis of serine starts with the oxidation of 3-phosphoglycerate (an intermediate from glycolysis) to 3-phosphohydroxypyruvate and NADH by phosphoglycerate dehydrogenase (EC 1.1.1.95). Reductive amination (transamination) of this ketone by phosphoserine transaminase (EC 2.6.1.52) yields 3-phosphoserine (O-phosphoserine) which is hydrolyzed to serine by phosphoserine phosphatase (EC 3.1.3.3).