Glycine

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Glycine
Glycine sample watch glass.jpg
Glycine on a watch glass
Names
IUPAC name
Aminoethanoic acid
Preferred IUPAC name
Aminoethanoic acid
Other names
2-Aminoacetic acid
Glycocoll
Properties
C2H5NO2
NH2-CH2-COOH
Molar mass 75.07 g/mol
Appearance White solid
Odor Odorless
Density 1.60 g/cm3
Melting point 233–240 °C (451–464 °F; 506–513 K) (decomposition)
Boiling point Decomposes
24.99 g/100 ml (25 °C)
39.1 g/100 ml (50 °C)
54.4 g/100 ml (75 °C)
67.2 g/100 ml (100 °C)[1]
Solubility Soluble in pyridine
Sparingly soluble in acetone, ethanol
Insoluble in diethyl ether, hydrocarbons
Solubility in ethanol 0.06 g/100 g
Vapor pressure ~0 mmHg
Acidity (pKa) 2.34 (carboxyl)
9.6 (amino)
Hazards
Safety data sheet Sigma-Aldrich
Flash point 176.67 °C
Lethal dose or concentration (LD, LC):
2,600 mg/kg (mouse, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Glycine (symbol Gly or G) is the simplest amino acid, which has a single hydrogen atom as its side chain, having the formula NH2-CH2-COOH. It is one of the proteinogenic amino acids.

Glycine is the only achiral proteinogenic amino acid.

Properties

Chemical

In aqueous solution, glycine itself is amphoteric: at low pH the molecule can be protonated with a pKa of about 2.4 and at high pH it loses a proton with a pKa of about 9.6 and can therefore form salts both with acids and bases.

Physical

Glycine is an odorless while solid, soluble in water, with a sweet taste.

Availability

Glycine is sold by chemical suppliers. It can also be bought online.

Preparation

Glycine can be synthesized by amination of chloroacetic acid with ammonia.

Preparation of glycine unnecessary, as it is too cheap to make it yourself from precursors.

Projects

  • Grow bacterial cultures
  • Buffering agent

Handling

Safety

Glycine has low toxicity.

Storage

Glycine is best kept in closed bottles, away from moisture.

Disposal

No special disposal is required. Discard it as you wish.

Gallery

References

  1. Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 765

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