Which of the following Zwitter ion form is correct?

The correct answer is option 1.

The term ‘Zwitterion’ is derived from the German word ‘zwitter’, which means ‘hybrid’ or ‘hermaphrodite’. A zwitterion is an ion that has both positive and negative electrical charges. Therefore, zwitterions are electrically neutral as the net formal charge is usually zero.

A zwitterion is a molecule that includes both positive and negative regions of charge. The existence of amino acids as dipolar ions in a solid state is called zwitterions. To evaluate whether a substance is zwitterionic or not, the pH range must be specified. This is because the zwitterion changes to an anion in the presence of sufficient alkaline solution, and zwitterion changes to a cation in the presence of sufficient acid solution.

Some key Characteristics of Zwitterion are:

i. They can be formed from compounds like ampholytes which contain both acid and base groups in their molecules.

ii. In this type of ion, the charged atoms are usually held together by one or more covalent bonds.

iii. Zwitterionic compounds have stable, separated unit electrical charges on atoms.

iv. These compounds contain quaternary ammonium cations.

Zwitterion Structure: Amino Acids

Amino acids are the most common example of zwitterions. They are made up of an ammonium or amino group which contains a positive charge as well as a carboxyl group which contains a negative charge. The zwitterion form of an amino acid is given below.

Apart from amino acids, any compound that contains acid and base centres can obtain a Zwitterion form. Some more examples include tricine, bicine, solid sulfamic acid, alkaloids like psilocybin amongst others.