Explain Isoelectric  pH

Isoelectric  pH:  Many  ionizable groups are  present  in  a  protein molecule. Depending on the pH of the medium, some of these groups act as proton donors and  some others act  as  proton  acceptors. Thus, proteins  are  amphoteric
compounds. At a specific pH, the protein exists as a dipolar ion (one positive and one negative ion)  or  zwitterion. So, at  this  pH  the net charge of the  protein -  becomes zero. This pH  is known as isoelectricpHorpI of the protein. Having no net charge, protein does not move to either electrode in an electric field.