Table of Contents
RNA vs DNA Key Difference: Why RNA Catalyzes Biological Reactions Exam Guide
RNA’s unique catalytic ability as ribozymes sets it apart from DNA—not shared adenine, double-stranding, or deoxyribose sugar—enabling enzyme-like reactions vital for protein synthesis and evolution in General Biology certification prep.
Question
Which of the following is a characteristic of RNA that differentiates it from DNA?
A. RNA can catalyze biological reactions
B. RNA contains adenine
C. RNA is double-stranded
D. RNA uses deoxyribose sugar
Answer
A. RNA can catalyze biological reactions
Explanation
RNA distinguishes itself from DNA through its catalytic capability as ribozymes, which are RNA molecules functioning as enzymes to accelerate biological reactions like peptide bond formation in the ribosome’s peptidyl transferase center, self-splicing introns, or RNase P-mediated tRNA processing, achieved via specific three-dimensional folding that positions substrates for phosphoryl transfer or cleavage without protein involvement. In contrast, DNA lacks this functionality due to its stable double-helix structure optimized for information storage rather than reactivity, while both share adenine (eliminating B), RNA is predominantly single-stranded (not C), and DNA uses deoxyribose whereas RNA employs ribose sugar (not D). This catalytic property supports the RNA world hypothesis, positioning RNA as both genetic material and catalyst in early evolution, with modern examples including group I/II introns and hammerhead ribozymes that lower activation energies through metal ion coordination and base-mediated general acid-base catalysis.