Which of the following amino acids will have +2 net charge at pH = 1?

Options

A. `H_(2)N-underset(H)underset(|)overset(CH_(3))overset(|)C-overset(O)overset(||)C-OH`
B.
C.
D.

Answer

To determine which amino acids will have a +2 net charge at pH = 1, we need to analyze the structure of each amino acid provided in the options and how they behave in an acidic environment.

### Step-by-Step Solution:

1. **Understanding pH = 1**:
- At pH 1, the environment is highly acidic. In such conditions, amino acids can accept protons (H⁺ ions) due to the presence of basic functional groups, primarily the amino group (-NH₂).

2. **Identifying Basic Groups**:
- Amino acids typically have at least one amino group (-NH₂) and one carboxyl group (-COOH). The amino group can accept a proton to become positively charged (-NH₃⁺), while the carboxyl group can release a proton and become negatively charged (-COO⁻).

3. **Analyzing Each Option**:
- **Option 1**: Check the structure of the amino acid. If it has only one amino group, it will gain one positive charge at pH 1. Thus, it will have a net charge of +1.
- **Option 2**: This amino acid has two basic nitrogen atoms (amino groups). Both can accept protons, leading to a total of +2 charge. Therefore, it will have a net charge of +2.
- **Option 3**: Similar to Option 1, if it has only one amino group, it will also have a net charge of +1 at pH 1.
- **Option 4**: This amino acid has two amino groups. Both can accept protons, resulting in a total of +2 charge. Thus, it will also have a net charge of +2.

4. **Conclusion**:
- The amino acids that will have a +2 net charge at pH = 1 are those with two amino groups that can accept protons. Based on the analysis, **Option 2 and Option 4** are the correct answers.

### Final Answer:
- The amino acids that will have a +2 net charge at pH = 1 are **Option 2 and Option 4**.