Which of the following statements is/are wrong

Options

A. All amino acids are optically active
B. Most of the naturally occuring amino acids are L - amino acids
C. Glycine is optically inactive
D. All amino acids contain a primary amino group except proline

Explanation

To determine which statements are wrong regarding amino acids, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement A: All amino acids are optically active.**
- **Analysis:** This statement is incorrect. Most amino acids are optically active due to the presence of a chiral carbon atom. However, glycine is an exception because it has two hydrogen atoms attached to its alpha carbon, making it achiral (not optically active).
- **Conclusion:** Statement A is wrong.

2. **Statement B: Most of the naturally occurring amino acids are L-amino acids.**
- **Analysis:** This statement is correct. In nature, the majority of amino acids found in proteins are in the L-form (levo) rather than the D-form (dextro).
- **Conclusion:** Statement B is true.

3. **Statement C: Glycine is optically inactive.**
- **Analysis:** This statement is correct. As mentioned earlier, glycine does not have a chiral center and is therefore optically inactive.
- **Conclusion:** Statement C is true.

4. **Statement D: All amino acids contain a primary amino group except proline.**
- **Analysis:** This statement is also correct. Most amino acids have a primary amino group (–NH2), but proline contains a secondary amino group (–NH) as it is part of a five-membered ring structure.
- **Conclusion:** Statement D is true.

### Final Conclusion:
- The only wrong statement is **Statement A**.

### Summary of Results:
- **Wrong Statement:** A
- **True Statements:** B, C, D