Which one of the followings is the proper sequence in protein synthesis?

Options

A. mRNA synthesis, mRNA amino acid complex, peptide chain
B. tRNA amino acid complex, mRNA synthesis, peptide chain
C. tRNA amino acid complex, peptide chain, mRNA synthesis
D. mRNA synthesis, tRNA amino acid complex, peptide chain

Answer

To determine the proper sequence in protein synthesis, we need to understand the steps involved in the process. Here’s a step-by-step breakdown of the protein synthesis process:

### Step 1: mRNA Synthesis
- The first step in protein synthesis is the transcription of DNA into messenger RNA (mRNA). This process occurs in the nucleus where the DNA serves as a template to synthesize a complementary strand of mRNA.

**Hint:** Remember that transcription is the process of converting DNA into mRNA.

### Step 2: Formation of tRNA Amino Acid Complex
- After mRNA is synthesized, it exits the nucleus and enters the cytoplasm. In the cytoplasm, transfer RNA (tRNA) molecules pick up specific amino acids. Each tRNA has an anticodon that is complementary to the codon on the mRNA. The tRNA with the attached amino acid forms a tRNA-amino acid complex.

**Hint:** Think of tRNA as the adapter that brings the correct amino acid to the growing protein chain based on the mRNA codon.

### Step 3: Translation and Peptide Chain Formation
- The mRNA binds to the ribosome, where translation occurs. The ribosome reads the mRNA codons and matches them with the appropriate tRNA anticodons. As the ribosome moves along the mRNA, the amino acids carried by tRNA are linked together to form a polypeptide chain (peptide chain).

**Hint:** The ribosome is the site where the actual assembly of the protein takes place, linking amino acids together.

### Conclusion
The proper sequence in protein synthesis is:
1. mRNA synthesis
2. tRNA amino acid complex formation
3. Peptide chain formation

Thus, the correct answer is: **mRNA synthesis, tRNA amino acid complex, and then peptide chain formation.**

### Final Answer
The correct option is **D: mRNA synthesis, tRNA amino acid complex, and peptide chain.**

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