Name an enzyme where RNA acts as a biological catalyst.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an enzyme that is made of RNA and acts as a biological catalyst.

2. **Identifying the Answer**: The enzyme that fits this description is called a "ribozyme."

3. **Defining Ribozyme**: A ribozyme is a type of RNA molecule that has catalytic properties, meaning it can accelerate chemical reactions, similar to protein enzymes.

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