A sample of live microbial cells was presented to a scientist . He decides to stop the synthesis of a particular protein in the sample cells. Suggest a modification in the part of the cell for the scientist to enable the prevention of that particular Protein synthesis.

Options

A. The DNA in the nucleus
B. An enzyme in the lysosomes
C. The polysaccharides in the cytoplasm
D. A phospholipid in the plasma membrane

Answer

To solve the question of how a scientist can stop the synthesis of a particular protein in a sample of live microbial cells, we need to understand the process of protein synthesis and identify the appropriate modification in the cell.

### Step-by-Step Solution:

1. **Understanding Protein Synthesis**:
- Protein synthesis occurs in two main stages: transcription and translation.
- In transcription, the DNA in the nucleus is transcribed to form messenger RNA (mRNA).
- In translation, the mRNA is translated into a protein by ribosomes in the cytoplasm.

2. **Identifying the Target for Modification**:
- To stop the synthesis of a specific protein, we need to inhibit the formation of mRNA or alter the DNA that encodes for that protein.
- Since the question asks for a modification in a part of the cell, we should focus on the nucleus, where DNA is located.

3. **Evaluating the Options**:
- **DNA in the nucleus**: Modifying the DNA will prevent the transcription of the specific mRNA, thus stopping the synthesis of the protein. This is a valid option.
- **Enzyme in lysosome**: Enzymes are proteins themselves and altering them would not prevent protein synthesis. This option is incorrect.
- **Polysaccharide in cytoplasm**: Polysaccharides are carbohydrates and do not play a direct role in protein synthesis. This option is irrelevant.
- **Phospholipid in plasma membrane**: Phospholipids are components of the cell membrane and do not affect protein synthesis. This option is also incorrect.

4. **Conclusion**:
- The best modification to stop the synthesis of a particular protein is to alter the **DNA in the nucleus**. This will prevent the transcription of the corresponding mRNA, thus inhibiting protein synthesis.

### Final Answer:
The scientist should modify the **DNA in the nucleus** to prevent the synthesis of the particular protein.

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