amino acids

• a-amino acids are organic molecules containing a carboxylic acid group and an amine group bonded to the same carbon atom
• Since amino acids have both an acidic COOH and a basic NH, functional group, amino acids have similar reactions to both carboxylic acids and amines.
• The amine group is basic and reacts with acids to make salts. As such, amino acids will also react with acids to form salts.
• The carboxylic acid group can react with alkalis to form salts and with alcohols to form esters.
• An amino acid reacts with an aqueous alkali such as sodium or potassium hydroxide to form a salt and water.
• Amino acids, like carboxylic acids, are easily esterified by heating with an alcohol in the presence of concentrated sulfuric acid.
• Within the structure of the amino acid, the basic amine group can accept a proton from the carboxylic acid group to form an ion containing both a positive and negative charge. This ion is known as a zwitterion.
• Zwitterions have no overall charge because the positive and negative charges cancel out.
• The isoelectric point is the pH at which the zwitterion is formed, and each amino acid has its own unique isoelectric point.
• If an amino acid is added to a solution with a pH greater than its isoelectric point, the amino acid behaves as an acid and loses a proton
• If an amino acid is added to a solution with a pH lower than its isoelectric point, the amino acid behaves as a base and gains a proton