are colorless crystalline substances which are generally soluable in water but insoluable in organ solvents
In solution, they exist as dipolar ions called zwitterions and are amphoterric; they have both basic and acidic properties.
When an amino acid has one acidic like the carboxylic group and one basic like the amino group it is called the neutral acid.
When there is more than one amino group, it is called the basic amino group and when it has more than one carboxylic group, it is called the acidic amino acid
Amino acids are grouped into two types: essential and non essential amino acids.
Plants are able to synthesize the amino acid need from simpler substances however; animals are unable to synthesize all the amino acid.
Essential amino acids are those which the body can’t synthesized but needs the,: while non essential amino acid are those that can be synthesized by the body: animals most therefore obtain the amino acid they can’t synthesized fro, redimate sources such as drets:
Amino acids have the general formula NH2RCHCOOH structurally.
All amino acid have the amino group (NH2) carboxylic (COOH) and the side chain (H) attached to the second carbon atom. The amino and carboxylic group remains the same but the side chain varies from one amino acid to another like these groups gives each amino acid its uniqueness.
Amino acids could be aliphatic or linear in the structure as found in valine or leocine. They could have hydroxyl group present as found in Theonine or Serine. Others have aromatic compounds (benzene ring) present e.g. Thyrosine. Others naturally occurring amino acid include Proline, Glutamine and Glycine.
Glycine is the simplest amino acid where R is simply Hydrogen
1- Properties of Amino acids
-They are colorless crystalline acids
-They are generally insoluble in organic solvent but soluble in water
-In a neutral aqueous solution, they exist as di-polar ion called Zwitterions
-They are amphoteric i.e. they posses acidic and basic properties
-Each amino acid has it own PH at which it exist in it neutral di-polar ion form
-The amphoteric property of amino acid is useful, biologically as it means that amino acid can act as buffers in solution, resisting changes in PH i.e. if the PH decreases, they will capture hydrogen ions and when PH increases, they donate hydrogen ions.
2- PEPTIDE BONDS
Amino acids are linked with each other like beats on a string to form proteins. The process begins with the lossing it hydroxyl groups to attach itself on the amino group of the other thereby forming a peptide bond or linkage. This is a condensation reaction bic a molecules of water is removed. Such a reaction result in a dipeptide bic two amino acid molecules is present. As the process continues. More amino acids are added forming a long chain called polypeptide. Thousands of amino acid is linked up in this manner forming proteins.
