Amino Acids
Organic Chemistry
A-Level
, Amino Acids
Amino acids have 2 functional groups:
- Amine NH2
- Carboxyl COOH
R2
Zwitterions
It is a dipolar ion
It has a positive and negative charge in its structure.
Amino acids exist as zwitterions
Zwitterion produces increases inter-molecular forces
They have high melting and boiling points.
Physical Properties
1. Amino acids have high melting points and are soluble in water. Simplest amino acid
is a solid.
2. Amino acids show optical activity
3. A mixture of amino acids can be separated by electrophoresis.
4. In both solid or aqueous solution, amino acids can exist as zwitterions depending on
the pH.
A zwitterion is a particle containing both a positive and negative ion.
It dissolves in water and has a high melting point as it is ionic.
Hence amino acid is less basic and is less acidic than a simple amine or a simple carboxylic
acid.
They are crystalline solid soluble in water.
2
Organic Chemistry
A-Level
, Amino Acids
Amino acids have 2 functional groups:
- Amine NH2
- Carboxyl COOH
R2
Zwitterions
It is a dipolar ion
It has a positive and negative charge in its structure.
Amino acids exist as zwitterions
Zwitterion produces increases inter-molecular forces
They have high melting and boiling points.
Physical Properties
1. Amino acids have high melting points and are soluble in water. Simplest amino acid
is a solid.
2. Amino acids show optical activity
3. A mixture of amino acids can be separated by electrophoresis.
4. In both solid or aqueous solution, amino acids can exist as zwitterions depending on
the pH.
A zwitterion is a particle containing both a positive and negative ion.
It dissolves in water and has a high melting point as it is ionic.
Hence amino acid is less basic and is less acidic than a simple amine or a simple carboxylic
acid.
They are crystalline solid soluble in water.
2
