Ribozymes are RNA molecules that function as what?

• A. Proteins
• B. Lipids
• C. RNA molecules that act as enzymes
• D. Nucleic acids

Answer: (C)

Ribozymes are RNA molecules that catalyze chemical reactions, acting as enzymes. This shows that RNA can do the job normally done by proteins—speeding up reactions—without needing to be a protein itself. The RNA folds into a precise shape that forms an active site, where the reaction occurs and where nucleotide functional groups participate in catalysis. That’s what makes ribozymes unique: they’re RNA-based catalysts rather than protein enzymes. While RNA is a type of nucleic acid, only some RNA molecules have this catalytic activity, whereas most enzymes are proteins.