Question

To isolate DNA from fungal cells, bacterial cells and plant cells, the enzymes required are respectively

• A. Chitinase, Lysozyme and Cellulase
• B. Cellulase, Protease and Lysozyme
• C. Lysozyme, Cellulase and Chitinase
• D. Lysozyme, Proteases and Ribonuclease

Hint:

Use Chitinase for fungi, Lysozyme for bacteria, and Cellulase for plants to effectively isolate DNA by breaking cell walls.

Answer 1

The Correct Option is A

• Definition of DNA Isolation: Enzymes are used to break down cell walls specific to different cell types to release DNA.
• Option Analysis:
  • (1) Chitinase, Lysozyme and Cellulase: Chitinase degrades the chitin in fungal cell walls, Lysozyme breaks down the peptidoglycan in bacterial cell walls, and Cellulase hydrolyzes cellulose in plant cell walls. This is correct.
  • (2) Cellulase, Protease and Lysozyme: Cellulase is for plants, Protease degrades proteins (not specific to cell walls), and Lysozyme is for bacteria. This mix is incorrect for fungal cells. This is incorrect.
  • (3) Lysozyme, Cellulase and Chitinase: Lysozyme is for bacteria, Cellulase for plants, and Chitinase for fungi, but the order is wrong (should be Chitinase, Lysozyme, Cellulase). This is incorrect.
  • (4) Lysozyme, Proteases and Ribonuclease: Lysozyme is for bacteria, Proteases for proteins, and Ribonuclease for RNA (not cell walls). This is unsuitable for fungi and plants. This is incorrect.
• Mechanism Insight: Each enzyme targets the unique cell wall component: chitin (fungi), peptidoglycan (bacteria), and cellulose (plants).
• Conclusion: The correct answer is (1) Chitinase, Lysozyme and Cellulase, as it matches the cell wall composition of each cell type.