To solve the assertion and reason question regarding glycine, we will break down the concepts step by step.
### Step-by-Step Solution:
1. **Understanding Glycine Structure**:
- Glycine is the simplest amino acid with the formula NH2CH2COOH. It contains both an amino group (-NH2) and a carboxylic acid group (-COOH).
2. **Isoelectric Point (pI)**:
- The isoelectric point (pI) is the pH at which an amino acid exists predominantly in its zwitterionic form, meaning it has no net charge. For glycine, the pI is approximately 6.0.
3. **Zwitterion Formation**:
- At the isoelectric point (pH 6.0), glycine exists as a zwitterion, which has both a positive charge (from the ammonium group, -NH3+) and a negative charge (from the carboxylate group, -COO-). These charges balance each other out, resulting in a net charge of zero.
4. **Behavior at pH 7**:
- When the pH of the solution is increased to 7, which is above the pI of glycine, the environment becomes slightly alkaline. In this condition, the carboxylic acid group remains deprotonated (as -COO-), while the amino group can lose a proton (H+), leading to the formation of a negatively charged species (-NH2).
5. **Conclusion on Electrical Neutrality**:
- At pH 7, glycine predominantly exists in a negatively charged form (as an anion), meaning the solution is not electrically neutral. Therefore, the assertion that an aqueous solution of glycine at pH 7 is not electrically neutral is correct.
6. **Correctness of Reason**:
- The reason provided states that the isoelectric point of glycine is 6.0, which is accurate. This reason explains why at pH 7, glycine does not remain neutral, as it has moved away from its isoelectric point.
### Final Answer:
Both the assertion (A) and the reason (R) are correct, and the reason is the correct explanation of the assertion.
