Question

Which of the following is/are CORRECT when two single complementary strands of DNA come together to form a double helix at a given temperature? $(\Delta S \text{ and } \Delta H \text{ are changes in entropy and enthalpy of the process, respectively.})$

• A. ∆S>0
• B. ∆S<0
• C. ∆H>0
• D. ∆H<0

Hint:

In biological systems like DNA, the process of hybridization typically results in a decrease in entropy and a release of energy (negative $\Delta H$).

Answer 1

The Correct Option is B, D

- When two complementary strands of DNA come together, the process involves a decrease in entropy, i.e., $\Delta S<0$ because the system becomes more ordered as the strands associate to form a double helix.
- The formation of hydrogen bonds and the overall stability of the double helix result in a negative enthalpy change, $\Delta H<0$. Thus, the correct answers are $\Delta S<0$ and $\Delta H<0$.