Which one of the following enzyme is not involved in recombinant DNA technology

Options

A. Exonuclease
B. Endonuclease
C. Ligase
D. Catalase

Answer

To determine which enzyme is not involved in recombinant DNA technology, we will analyze each option provided:

1. **Exonuclease**: This enzyme removes nucleotides from the ends of a DNA molecule. While it can be used in some DNA manipulation processes, it is not a primary enzyme used in recombinant DNA technology. Its main function is to trim DNA from the ends rather than facilitating the cutting and joining of DNA fragments.

2. **Endonuclease**: This enzyme cuts DNA at specific internal sites within the DNA molecule. Endonucleases, particularly restriction enzymes, are crucial in recombinant DNA technology as they allow for the precise cutting of DNA at specific sequences, enabling the insertion of new genetic material.

3. **Ligase**: DNA ligase is an essential enzyme in recombinant DNA technology. It is responsible for joining together DNA fragments by forming phosphodiester bonds, which is vital for creating recombinant DNA molecules.

4. **Catalase**: This enzyme breaks down hydrogen peroxide into water and oxygen. It is not involved in DNA manipulation or recombinant DNA technology. Catalase is primarily involved in protecting cells from oxidative damage rather than in genetic engineering processes.

Based on the analysis:

**Answer**: The enzyme that is not involved in recombinant DNA technology is **D. Catalase**.