Update particular columns only the table in dbcontext entity

Hi Everyone,
                   I need to update entity table only particular columns. Here i have a database table in enity class and i created one separate class to pass the values from controller to model through service. Here is my code:
This class i created one,  Class1:
public class Class1     {         public virtual int PKID         {             get;             set;         }         public virtual string Name         {             get;   &n ...