Which type of molecule is known to have catalytic activity apart from proteins?

RNA is recognized for its catalytic activity apart from proteins, primarily due to the presence of ribozymes. Ribozymes are RNA molecules that can catalyze biochemical reactions, similar to how protein enzymes operate. This activity was a significant discovery that expanded the understanding of the roles nucleic acids can play in cellular processes.

Unlike proteins, which are the traditional catalysts in biological systems, certain RNA sequences have the ability to fold into specific three-dimensional shapes that allow them to facilitate reactions, such as the cleavage and ligation of RNA itself. This catalytic function supports theories regarding the early stages of life on Earth, where RNA may have played a central role in both genetic material and enzymatic functions.

The other types of molecules listed do not possess inherent catalytic activities comparable to those of RNA. DNA serves primarily as the genetic blueprint and lacks the catalytic functionality. Carbohydrates and lipids primarily serve structural and energy storage roles, respectively, rather than catalytic functions. Thus, RNA stands out as the unique molecule capable of catalysis outside of proteins.