Which among the given enzymes is not composed of RNA?

Options

A. Ribonuclease P
B. Snurp
C. RNA polymerase
D. Peptidyl tranferase

Answer

To determine which enzyme among the given options is not composed of RNA, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Enzymes**: The options given are:
- Ribonuclease P
- SNURP (Small Nuclear Ribonucleoproteins)
- RNA Polymerase
- Peptidyl Transferase

2. **Analyze Ribonuclease P**:
- Ribonuclease P is an enzyme that is composed of RNA and protein. It plays a role in processing precursor tRNA molecules.
- **Conclusion**: Ribonuclease P contains RNA.

3. **Analyze SNURP (Small Nuclear Ribonucleoproteins)**:
- SNURP is a complex that includes small nuclear RNA (snRNA) and proteins. It is involved in the splicing of pre-mRNA.
- **Conclusion**: SNURP contains RNA.

4. **Analyze RNA Polymerase**:
- RNA Polymerase is an enzyme that synthesizes RNA from a DNA template. It is composed of protein but interacts with RNA during the transcription process.
- **Conclusion**: RNA Polymerase is associated with RNA but is not composed of RNA itself.

5. **Analyze Peptidyl Transferase**:
- Peptidyl Transferase is an enzymatic activity of the ribosome that forms peptide bonds between amino acids during protein synthesis. It is associated with ribosomal RNA (rRNA) but is primarily a protein function.
- **Conclusion**: Peptidyl Transferase has RNA properties due to its association with rRNA.

6. **Final Conclusion**:
- Among the given options, **SNURP** is the only one that is not an enzyme composed of RNA. Instead, it is a complex of RNA and protein. However, if we strictly consider enzymes, **RNA Polymerase** is the one that is not composed of RNA itself.

### Answer:
The enzyme that is not composed of RNA is **RNA Polymerase**.