What is the temperature and time used to denature enzymes during the kiwi DNA isolation process?

• A. 100°C for 5 minutes
• B. 60°C for 15 minutes
• C. 37°C for 60 minutes
• D. 4°C for 10 minutes

Answer: (B)

Denatured enzymes are inactivated when their proteins lose their folded structure, which stops their catalytic activity. In kiwi DNA isolation, heating to 60°C for about 15 minutes inactivates nucleases that would otherwise chew up the DNA, helping to keep the DNA intact. This temperature is high enough to unfold enzymes but not so extreme or prolonged that the DNA is overly damaged, making it a practical balance for this step. The other options either don’t inactivate enzymes effectively (37°C), are more likely to damage DNA or be excessive (100°C), or only slow enzymes without stopping them (4°C).