For every single amino acid incorporated in peptide chain ___ ATP and _____GTP molecules are used.

Options

A. 1,4
B. 1,6
C. 1,2
D. 1,3

Answer

To answer the question regarding the number of ATP and GTP molecules used for the incorporation of a single amino acid into a peptide chain, we can break down the process step by step.

### Step-by-Step Solution:

1. **Understanding the Role of ATP and GTP in Protein Synthesis**:
- ATP (Adenosine Triphosphate) and GTP (Guanosine Triphosphate) are both energy-carrying molecules that play crucial roles in protein synthesis.
- ATP is primarily used for the charging of tRNA, while GTP is involved in various stages of translation.

2. **Charging of tRNA**:
- Before an amino acid can be added to the growing peptide chain, it must first be attached to its corresponding tRNA. This process is known as "charging" the tRNA.
- **ATP Requirement**: The charging of one tRNA requires the hydrolysis of 1 ATP molecule.

3. **Role of GTP in Translation**:
- During the translation process, GTP is utilized in several steps:
- **Initiation**: 1 GTP is used to form the 30S initiation complex of the ribosome.
- **Elongation**: 2 GTP molecules are used:
- One GTP is used for the positioning of the incoming tRNA at the ribosome.
- Another GTP is used for the translocation of the ribosome along the mRNA.
- **Termination**: 1 GTP is used to release the newly formed polypeptide chain from the ribosome.

4. **Total Count of ATP and GTP**:
- From the above steps, we can summarize:
- **1 ATP** is used for charging the tRNA.
- **4 GTP** molecules are used in various stages of translation (1 for initiation, 2 for elongation, and 1 for termination).

5. **Final Answer**:
- Therefore, for every single amino acid incorporated into the peptide chain, **1 ATP** and **4 GTP** molecules are used.

### Conclusion:
The correct answer to the question is: **1 ATP and 4 GTP**.