In protein synthesis, Which of the following are required for the synthesis of charged tRNA ?

Options

A. Amino acid , GTP initiation codon , ribosome
B. Amino acid, ATP,Mg^(++)`, enzyme , tRNA
C. Amino acid ATP `K^(+)`, enzyme , mRNA
D. Aminoacyl tRNA, ribosome , inititaion codon, release factor.

Answer

To answer the question regarding the requirements for the synthesis of charged tRNA (also known as aminoacyl-tRNA) in protein synthesis, we can break down the necessary components step by step.

### Step-by-Step Solution:

1. **Understanding Charged tRNA**: Charged tRNA, or aminoacyl-tRNA, is a tRNA molecule that is covalently bonded to an amino acid. This process is crucial for protein synthesis as it ensures that the correct amino acid is added to the growing polypeptide chain during translation.

2. **Requirement of Amino Acid**: The first requirement for the synthesis of charged tRNA is the amino acid itself. The amino acid is essential because it is the building block that will be added to the polypeptide chain. The amino acid must be activated and attached to the tRNA by an enzyme called aminoacyl-tRNA synthetase.

3. **Role of ATP**: Although ATP is not explicitly mentioned in the question, it is important to note that ATP is required for the activation of the amino acid. The amino acid is converted to an aminoacyl-AMP (adenosine monophosphate) before it is transferred to the tRNA, forming charged tRNA. Thus, ATP is indirectly involved in this process.

4. **Requirement of GTP**: GTP (guanosine triphosphate) is also necessary during the initiation phase of protein synthesis. It is involved in the formation of the initiation complex and helps in the recruitment of the ribosome to the mRNA.

5. **Initiation Codon**: The initiation codon (typically AUG) is crucial as it signals the start of translation. It ensures that the ribosome knows where to begin synthesizing the protein.

6. **Role of Ribosome**: The ribosome is the cellular machinery that facilitates the translation of mRNA into a protein. It provides the site where charged tRNA can deliver the appropriate amino acids according to the sequence of codons on the mRNA.

### Conclusion:
The four main requirements for the synthesis of charged tRNA are:
- Amino Acid
- GTP
- Initiation Codon
- Ribosome

Thus, the correct answer is option number one, which includes all these components.