Here's why:

* Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are typically made of proteins.

* Ribozymes are a special type of RNA molecule that can act as a catalyst. RNA is a nucleic acid, not a protein.

Key Takeaways:

* Most enzymes are proteins.

* Ribozymes are RNA molecules that have catalytic activity.

* Ribozymes demonstrate that protein is not the only molecule capable of enzyme activity.

Let me know if you have any other questions!