An extra carboxylic group is present in

Options

A. Aspartate
B. Lysine
C. Tyrosine
D. Phenylalanine

Explanation

To determine which compound has an extra carboxylic group, we will analyze the structures of the given options: amino acids, specifically phenylalanine, tyrosine, lysine, and aspartate.

### Step-by-Step Solution:

1. **Understanding Carboxylic Groups**:
- A carboxylic group (-COOH) is a functional group that consists of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group (-OH).

2. **Analyzing Amino Acids**:
- Amino acids typically have one carboxylic group as part of their structure. The general structure of an amino acid includes:
- A central carbon (C)
- An amino group (-NH2)
- A hydrogen atom (H)
- A carboxylic group (-COOH)

3. **Examining Each Option**:
- **Phenylalanine**:
- Structure includes one carboxylic group. No extra carboxylic group is present.
- **Tyrosine**:
- Similar to phenylalanine, it has one carboxylic group. No extra carboxylic group is present.
- **Lysine**:
- Contains one carboxylic group and additional amine groups. No extra carboxylic group is present.
- **Aspartate**:
- Structure includes one carboxylic group attached to the central carbon and an additional carboxylic group attached to the side chain (CH2). This means aspartate has an extra carboxylic group.

4. **Conclusion**:
- Based on the analysis, **aspartate** is the amino acid that has an extra carboxylic group in its structure.

### Final Answer:
**Aspartate** has an extra carboxylic group.