In prokaryotes , which ribozyme helps in peptide bond formation ?

Options

A. 18S rRNA
B. 165 rRNA
C. 285 rRNA
D. 235 rRNA

Answer

To solve the question "In prokaryotes, which ribozyme helps in peptide bond formation?", we can follow these steps:

### Step 1: Understand the Role of Ribozymes
- A ribozyme is an RNA molecule that can catalyze biochemical reactions, similar to the action of enzymes. In the context of protein synthesis, ribozymes play a crucial role during translation, particularly in the formation of peptide bonds.

**Hint:** Remember that ribozymes are RNA molecules that can act like enzymes.

### Step 2: Identify the Ribosomal Components in Prokaryotes
- Prokaryotic ribosomes are composed of two subunits: the small subunit (30S) and the large subunit (50S). The large subunit contains the ribosomal RNA that is responsible for the peptidyl transferase activity, which is essential for peptide bond formation.

**Hint:** Prokaryotic ribosomes are 70S, made up of 30S and 50S subunits.

### Step 3: Determine the Specific rRNA Involved
- The large subunit (50S) of prokaryotic ribosomes contains 23S rRNA, which is the ribozyme that facilitates the formation of peptide bonds during protein synthesis. The peptidyl transferase activity, which is crucial for peptide bond formation, is attributed to this 23S rRNA.

**Hint:** Focus on the large subunit of the ribosome and its specific rRNA components.

### Step 4: Eliminate Incorrect Options
- The question provides several options: 16S rRNA, 18S rRNA, 25S rRNA, and 23S rRNA.
- 16S rRNA is part of the small subunit (30S) and does not participate in peptide bond formation.
- 18S rRNA is found in eukaryotic ribosomes (40S subunit), not in prokaryotes.
- 25S rRNA is also found in eukaryotic ribosomes (60S subunit).
- 23S rRNA is the correct answer as it is part of the 50S subunit and is responsible for the peptidyl transferase activity.

**Hint:** Compare the rRNA types with their respective ribosomal subunits and functions.

### Conclusion
- The ribozyme that helps in peptide bond formation in prokaryotes is **23S rRNA**.

**Final Answer:** 23S rRNA