Nature of aqueous solutions of two different amino acids X and Y are acidic and basic. Now X and Y are.

Options

A. Alanine and valine
B. Aspartic acid and aspargine
C. Glutamine and gutamine acid
D. Aspartic acid and lysine

Answer

To determine the nature of the aqueous solutions of the two amino acids X and Y, where X is acidic and Y is basic, we need to identify which amino acids fit these descriptions.

### Step-by-Step Solution:

1. **Understand Amino Acids Classification**:
- Amino acids can be classified as acidic, basic, or neutral based on their side chains (R groups).
- Acidic amino acids have side chains that can donate protons (H⁺) in solution, making the solution acidic.
- Basic amino acids have side chains that can accept protons, making the solution basic.

2. **Identify Acidic Amino Acids**:
- The common acidic amino acids include:
- Aspartic acid (Asp, D)
- Glutamic acid (Glu, E)

3. **Identify Basic Amino Acids**:
- The common basic amino acids include:
- Lysine (Lys, K)
- Arginine (Arg, R)
- Histidine (His, H)

4. **Evaluate the Options**:
- The question provides several pairs of amino acids:
- **Option A**: Alanine and Valine (both neutral)
- **Option B**: Aspartic acid and Asparagine (Asp is acidic, Asn is neutral)
- **Option C**: Glutamine and Glutamic acid (Gln is neutral, Glu is acidic)
- **Option D**: Aspartic acid and Lysine (Asp is acidic, Lys is basic)

5. **Select the Correct Pair**:
- From the evaluation:
- **Option D (Aspartic acid and Lysine)** is the correct answer as it contains one acidic amino acid (Aspartic acid) and one basic amino acid (Lysine).

### Conclusion:
X is Aspartic acid (acidic) and Y is Lysine (basic). Therefore, the correct answer is Option D: Aspartic acid and Lysine.