Amino Acids | Definition, Properties, Glycine |

Amino Acids.

Amino acids are the edifice blocks of the molecular construction of the of import together with rattling complex shape of compounds known equally proteins. The proteins on hydrolysis yield mixtures of the ingredient amino acids. Therefore, to empathize the construction together with chemical scientific discipline of proteins, nosotros receive got to kickoff undertake the report of amino acids.

Amino Acids are compounds that comprise at to the lowest degree ane carboxyl grouping (-COOH) together with ane amino grouping ( NH2). In α-amino acids, the amino grouping is located on the alpha (α) carbon (the carbon adjacent to the carboxyl group). Their full general Formula is:

Where R may locomote H, alkyl group, or may locomote quite complex containing other functional groups.

Properties of amino acids.

PHYSICAL PROPERTIES.

1. Amino acids are colourless, crystalline substances having sugariness taste. They melt amongst decomposition at high temperature.
2. They are soluble inward polar solvents similar H2O together with insoluble inward organic solvents such equally crude oil ether, ethanol together with benzene.
3. Excepting glycine, all α-amino acids possess an asymmetric carbon atom together with are optically active.
   
4. Their H2O solutions are neutral to litmus owing to the formation of their internal tabular array salt or Zwitterion.
   
5. From Natural Proteins. Natural proteins are polymers of dissimilar amino acid units joined to each other past times amide linkages. Thus proteins when boiled amongst dilute muriatic acid yield mixtures of amino acids. The mixture of amino acid is esterified together with the private esters separated past times fractional distillation. They are together with thus hydrolysed to larn the gratuitous amino acids. Physical techniques such equally fractional precipitation, chromatography, together with electrophoresis are forthwith widely used for the recovery of amino acids.

CHEMICAL PROPERTIES.

Amino acids laissez passer on reactions feature of both carboxylic acids amines. α-Amino acids laissez passer on the next reactions:

REACTION OF THE CARBOXYL GROUP.

(1) Salt Formation With NaOH.

(2) Reduction With LiAlH4.

Glycine.

It is thus named because of its sugariness gustation (Greek, glycys = sweet).

Preparation of glycine.

Glycine may locomote readily obtained inward the laboratory past times treating chloroacetic acid amongst concentrated ammonium hydroxide solution.

A sample of pure glycine tin equally good locomote prepared by Gabriel Phthalimide Synthesis.

Properties of glycine.

Glycine is white crystalline substance, mp 235°C amongst decomposition. It is rattling soluble inward H2O exactly insoluble inward ethanol together with ether. Its aqueous solutions are neutral owing to the formation of Zwitterion.

It gives all the full general reactions of α-amino acids already discussed.

Glycine Uses.

Glycine is used:

1. In medicine for certainly muscular disorders.
2. For the industry of resins together with varnishes.