Iso-electric point of alanine is (pH = 6). At which pH, maximum concentration of zwitter ion of alanine will be present?

Options

A. pH gt 6
B. pH lt 6
C. pH = 6
D. pH = 7

Explanation

To determine the pH at which the maximum concentration of zwitterion of alanine is present, we can follow these steps:

### Step 1: Understand the concept of zwitterion
A zwitterion is a molecule that has both positive and negative charges but is overall neutral. In the case of amino acids like alanine, the zwitterionic form occurs when the amino group (-NH3+) is positively charged and the carboxyl group (-COO-) is negatively charged.

**Hint:** Remember that zwitterions are neutral molecules with both positive and negative charges.

### Step 2: Identify the isoelectric point (pI)
The isoelectric point (pI) is the pH at which the molecule exists predominantly in its zwitterionic form. For alanine, it is given that the isoelectric point is pH 6.

**Hint:** The isoelectric point is where the net charge of the molecule is zero.

### Step 3: Relate pH to zwitterion concentration
At the isoelectric point, the concentration of the zwitterionic form of alanine is at its maximum. This is because at this pH, the rates of protonation and deprotonation of the amino and carboxyl groups balance out, leading to the highest concentration of the zwitterionic form.

**Hint:** The maximum concentration of zwitterion occurs specifically at the isoelectric point.

### Step 4: Conclusion
Since the isoelectric point of alanine is given as pH 6, the maximum concentration of zwitterion of alanine will be present at this pH.

**Final Answer:** The maximum concentration of zwitter ion of alanine will be present at pH 6.