Question
Question: At iso-electric point: A.Conc of cation is equal to conc of anion B.Net charge is zero C.Maxim...
At iso-electric point:
A.Conc of cation is equal to conc of anion
B.Net charge is zero
C.Maximum conc. of di-polar ion (zwitterion) will be present
D.All of the above
Solution
So, for this question we should first understand the features of isoelectric point pI. Iso-electric point is the point which is interrelated to pH. This term mainly comes under the topic of electrophoresis
Complete step by step answer:
Let us first understand the isoelectric point;
The pH at which a molecule does not bear a net electrical charge or is electrically neutral is the isoelectric point. Now, another term related to this topic is zwitterion. So zwitterion is basically a molecule of at least two functional groups: one with a positive charge and the other with a negative charge, with a zero as total charge.
So, in order to make the charge zero, the total number of cations and anions must be equal. Hence option A is correct.
From the above explanation it is clear that the charge is zero in an isoelectric point and hence option B is also correct.
As the electric charge is neutral the concentration of zwitterion form will also be more in this point because at isoelectric point both positive and negative form of a substance exist and zwitterion is one such and hence option C is also correct.
Hence, option D is the correct answer as all the above options are correct.
Note:
The pI value at a given pH will influence a molecule's solubility. These molecules have minimum solubility at the pH corresponding to their pI in water or salt solutions and frequently precipitate out of the solution. The surface of the protein is primarily negatively charged at solution pH that is above pI, and hence repulsive forces can be exhibited by like-charged molecules.