Why is it that RNA can catalyze reactions but DNA cannot?

• A. RNA contains thymine, which is essential for catalytic activity.
• B. DNA is single-stranded and therefore cannot form active sites for catalysis.
• C. DNA is more chemically reactive than RNA, making it unsuitable for catalysis.
• D. RNA has a 2'-hydroxyl group that allows it to adopt diverse three-dimensional structures necessary for catalysis.

Answer: (D)

Verified step by step guidance

1. Understand the structural differences between RNA and DNA. RNA contains ribose sugar, which has a hydroxyl (-OH) group attached to the 2' carbon, while DNA contains deoxyribose sugar, which lacks this 2'-hydroxyl group.
2. Recognize the significance of the 2'-hydroxyl group in RNA. This functional group increases RNA's chemical reactivity and flexibility, allowing it to form diverse three-dimensional structures.
3. Learn about RNA's ability to fold into complex shapes. The presence of the 2'-hydroxyl group enables RNA to form intricate secondary and tertiary structures, such as hairpins, loops, and pseudoknots, which are essential for catalytic activity.
4. Understand why DNA cannot catalyze reactions. DNA lacks the 2'-hydroxyl group, making it less chemically reactive and unable to adopt the diverse structures required for catalysis. DNA's primary role is to store genetic information in a stable form.
5. Explore examples of RNA catalysis. RNA molecules, such as ribozymes, utilize their structural versatility to catalyze biochemical reactions, including peptide bond formation during protein synthesis and self-splicing of introns.