Question

Zwitterionic form of an Amino acid, is put into an acidic medium, then that structure will move towards which electrode in electric fields?

• A. Anode
• B. Cathode
• C. Nowhere
• D. Cathode & Anode both

Answer 1

The correct option is B Cathode

• A zwitterion is a molecule has a positive and a negative electrical charge thus, the net charge of the entire molecule is zero.
  
• An amino acid contains an amine group (basic) and a carboxylic group (acidic).
• The -NH2 group is the stronger base, and so it picks up H+ from the -COOH group to form a zwitterion.
  
• If the pHis decreased by adding an acid to a solution of an amino acid, the -COO- part of the zwitterion picks up a hydrogen ion.
  
• Thus, the amino acid would move toward the cathode (the negative electrode).
  
• The correct answer is OPTION B.