Enzymes are biocatalysts. They catalyze biochemical reactions. In general, they reduce the activation energy of reactions. Many physicochemical processes are enzyme-mediated. Which of the following reactions is not enzyme-mediated in the biological system?
1. Dissolving CO2 in water
2. Untwining the two strands of DNA
3. Hydrolysis of sucrose
4. Formation of peptide bond
Page 155, XI NCERT