Ribozyme is

Options

A. Antibiotic
B. Hormone
C. Proteinaceous enzyme
D. RNA enzyme.

Answer

### Step-by-Step Solution:

1. **Understanding the Term "Ribozyme":**
- A ribozyme is a type of RNA molecule that has the ability to act as an enzyme. Unlike most enzymes, which are proteins, ribozymes are made of RNA.

2. **Identifying the Options:**
- The options provided are:
- Antibiotic
- Hormone
- Proteinaceous enzyme
- RNA enzyme

3. **Analyzing Each Option:**
- **Antibiotic:** Antibiotics are typically substances produced by microorganisms that inhibit the growth of or destroy bacteria. They are not related to ribozymes.
- **Hormone:** Hormones are signaling molecules, often proteins or steroids, that regulate physiological processes. They do not include ribozymes.
- **Proteinaceous enzyme:** Most enzymes are proteins, but ribozymes are specifically RNA molecules that function as enzymes, making this option incorrect.
- **RNA enzyme:** This option correctly describes ribozymes, as they are RNA molecules that catalyze biochemical reactions.

4. **Conclusion:**
- The correct answer is **RNA enzyme** because ribozymes are RNA molecules that possess enzymatic activity.

### Final Answer:
Ribozyme is an **RNA enzyme**.

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