The number of amino and carboxyl groups in an amino acid is never -

Options

A. 1 and 1
B. 2 and 1
C. 3 and 1
D. 1 and 2

Answer

To answer the question about the number of amino and carboxyl groups in an amino acid, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Amino Acids**:
- Amino acids are the building blocks of proteins. Each amino acid consists of a central carbon atom bonded to four different groups: an amino group (–NH2), a carboxyl group (–COOH), a hydrogen atom (–H), and a variable R group (side chain).

2. **Identifying Functional Groups**:
- In every amino acid, there is always one amino group (–NH2) and one carboxyl group (–COOH). This is a defining characteristic of amino acids.

3. **Analyzing the Options**:
- The question asks for the number of amino and carboxyl groups in an amino acid. Since each amino acid has one of each, we can conclude that the number of amino groups is 1 and the number of carboxyl groups is also 1.

4. **Conclusion**:
- Therefore, the number of amino and carboxyl groups in an amino acid is never more than 1 for each type. The correct answer to the question is that the number of amino and carboxyl groups in an amino acid is never **zero**.

### Final Answer:
The number of amino and carboxyl groups in an amino acid is never **zero**.

---