Question

Which sugar is present in DNA?

• A. Ribose
• B. Arabinose
• C. Deoxyribose
• D. Glucose

Hint:

Remember that the "Deoxy" in Deoxyribose denotes the loss of an oxygen atom at the C2' position compared to Ribose ($\text{C}_5\text{H}_{10}\text{O}_4$ vs $\text{C}_5\text{H}_{10}\text{O}_5$).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Nucleic acids contain a pentose (five-carbon) sugar that forms the structural backbone of their polymer chains.

Step 2: Detailed Explanation:
- DNA (Deoxyribonucleic Acid) contains $\beta$-D-2-deoxyribose.
This pentose sugar has a hydrogen atom ($\text{-H}$) instead of a hydroxyl group ($\text{-OH}$) at the 2' carbon position.
- RNA (Ribonucleic Acid) contains ribose sugar, which has a hydroxyl group ($\text{-OH}$) at the 2' carbon position.
- The absence of the 2' hydroxyl group makes DNA more chemically stable and resistant to alkaline hydrolysis than RNA.

Step 3: Final Answer:
The sugar present in DNA is Deoxyribose.