An `alpha`-amino acid exists as, `overset(+)(NH_3)-underset(R)underset(|)CH-COOH` at (pH=2) and its isoelectric point is 6. The amino acid at pH 10.97 will exist as :

Options

A. `overset(+)(NH_3)-underset(R)underset(|)CH-COO^-`
B. `NH_2-underset(R)underset(|)CH-COO^-`
C. `NH_2-underset(R)underset(|)CH-COOH`
D. `overset(+)(NH_2)-underset(R)underset(|)overset(-)CH-COOH`

Explanation

To determine the form of the alpha-amino acid at pH 10.97, we need to analyze the behavior of amino acids at different pH levels, particularly in relation to their isoelectric point (pI).

### Step-by-Step Solution:

1. **Understanding the Structure at pH 2**:
At pH 2, the amino acid exists in its cationic form:
\[ \text{NH}_3^+ - \text{CH} - \text{COOH} \]
This indicates that the amino group is protonated (NH3+) and the carboxylic acid group is still in its acidic form (COOH).

**Hint**: Remember that at low pH, amino acids tend to gain protons, leading to a positively charged form.

2. **Identifying the Isoelectric Point (pI)**:
The isoelectric point (pI) is given as 6. At this pH, the amino acid exists in a zwitterionic form:
\[ \text{NH}_3^+ - \text{CH} - \text{COO}^- \]
Here, the amino group is still protonated, while the carboxylic acid group has lost a proton and exists as a carboxylate ion (COO^-).

**Hint**: The zwitterionic form is neutral overall but has both a positive and a negative charge.

3. **Analyzing the Form at pH 10.97**:
At pH 10.97, which is above the isoelectric point (pI = 6), the amino acid will lose the proton from the amino group:
\[ \text{NH}_2 - \text{CH} - \text{COO}^- \]
In this form, the amino group is deprotonated (NH2), and the carboxylic group remains deprotonated (COO^-). This indicates that the amino acid is now in its anionic form.

**Hint**: At high pH, amino acids lose protons from both the amino and carboxylic groups, leading to a negatively charged form.

4. **Conclusion**:
Therefore, at pH 10.97, the amino acid exists as:
\[ \text{NH}_2 - \text{CH} - \text{COO}^- \]
This form is characterized by a net negative charge due to the presence of the carboxylate ion.

**Final Answer**: The amino acid at pH 10.97 will exist as:
\[ \text{NH}_2 - \text{CH} - \text{COO}^- \]