Question

Why is DNA denatured?

Answer 1

DNA denaturation:

1. The hydrogen bonds between two strands are destroyed during the denaturation process, resulting in two single strands.
2. The DNA covalent bonds are unaffected.

DNA denaturation occurs because:

1. When a DNA solution is heated to 90°C or more, there is enough kinetic energy to completely denature the DNA, forcing it to separate into single strands.
2. Chemical reagents like urea and formamide speed up the denaturation process.
3. The presence of numerous OH– ions causes hydrogen bonds between base pairs of two strands of DNA to dissolve at high pH (>11.3).
4. DNA is denaturized as a result of this process.
5. Hydrogen bonds are destabilized by low salt concentrations.
6. By altering the electronegative centers of nitrogenous bases, formaldehyde, and urea have a tendency to generate hydrogen bonds with nitrogen bases, and aldehydes also hinder hydrogen bonding between base pairs.