What is a ribozyme and what is its significance in cellular processes?

• A. A ribozyme is a lipid that stabilizes RNA structures.
• B. A ribozyme is a DNA molecule that assists in RNA transcription.
• C. A ribozyme is a protein that catalyzes RNA synthesis.
• D. A ribozyme is an RNA molecule with catalytic activity, playing a role similar to enzymes in biochemical reactions.

Answer: (D)