Which step of translation does not consume high energy `PO_(4)` bond?

Options

A. Translocation
B. tRNA activation
C. Amino acid activation
D. Peptydyl transferase reaction

Answer

To solve the question "Which step of translation does not consume high energy `PO_(4)` bond?", we will analyze the different steps involved in the translation process and identify which one does not require energy in the form of high-energy phosphate bonds like ATP or GTP.

### Step-by-Step Solution:

1. **Understanding Translation**:
- Translation is the process of synthesizing proteins from amino acids based on the sequence of codons in mRNA. It involves several steps including initiation, elongation, and termination.

2. **Identifying Steps Involved in Translation**:
- The main steps of translation include:
- tRNA activation (charging)
- Initiation
- Codon recognition
- Translocation
- Peptidyl transferase reaction

3. **Analyzing Each Step for Energy Consumption**:
- **tRNA Activation**: This step involves the charging of tRNA with its corresponding amino acid and requires ATP. (Consumes high energy)
- **Initiation**: This step requires energy to assemble the ribosome and the initiation complex, which also consumes GTP. (Consumes high energy)
- **Codon Recognition**: This step requires energy for the correct pairing of tRNA with mRNA codons, typically using GTP. (Consumes high energy)
- **Translocation**: This step involves the movement of the ribosome along the mRNA, which requires GTP. (Consumes high energy)
- **Peptidyl Transferase Reaction**: This step is where the peptide bond is formed between amino acids, and it does not require any high-energy phosphate bond. It is catalyzed by the ribosomal RNA (rRNA) and does not consume ATP or GTP. (Does not consume high energy)

4. **Conclusion**:
- The only step in translation that does not consume a high-energy phosphate bond is the **Peptidyl Transferase Reaction**.

### Final Answer:
The step of translation that does not consume high energy `PO_(4)` bond is the **Peptidyl Transferase Reaction**.

---