Optically active amino acid is/are

Options

A. Leucine
B. Glycine
C. Glucolic acid
D. Valine

Explanation

To determine which amino acids are optically active, we need to identify the presence of chiral centers in their structures. A chiral carbon atom is one that has four different groups attached to it, making the molecule capable of existing in two non-superimposable mirror images (enantiomers).

### Step-by-Step Solution:

1. **Understand the Concept of Optical Activity**:
- Optical activity refers to the ability of a compound to rotate plane-polarized light. This property is exhibited by compounds that have chiral centers.

2. **Identify Chiral Centers**:
- A chiral center is typically a carbon atom that is bonded to four different groups. If an amino acid has at least one chiral carbon, it is considered optically active.

3. **Analyze Each Amino Acid**:
- **Leucine**:
- Structure: CH3-CH(CH3)-CH2-COOH
- Chiral Center: The second carbon (attached to CH3, CH2, COOH, and NH2) is chiral.
- Conclusion: Leucine is optically active.

- **Glycine**:
- Structure: NH2-CH2-COOH
- Chiral Center: Glycine has two hydrogen atoms attached to the central carbon (NH2 and COOH are the other two groups).
- Conclusion: Glycine is not optically active (no chiral center).

- **Valine**:
- Structure: CH3-CH(CH3)-COOH
- Chiral Center: The second carbon (attached to CH3, CH3, COOH, and NH2) is chiral.
- Conclusion: Valine is optically active.

- **Glutamic Acid**:
- Structure: HOOC-CH2-CH(COOH)-NH2
- Chiral Center: The second carbon (attached to COOH, NH2, CH2, and another COOH) is chiral.
- Conclusion: Glutamic acid is optically active.

4. **Final Conclusion**:
- The optically active amino acids from the given options are **Leucine, Valine, and Glutamic Acid**.

### Summary of Results:
- **Optically Active Amino Acids**: Leucine, Valine, Glutamic Acid
- **Optically Inactive Amino Acid**: Glycine