Which one occurs in cell walls of Gram (+) bacteria only ?

Options

A. Peptidoglycan
B. Lipopolysaccharide
C. Teichoic acid
D. None of the above.

Answer

**Step-by-Step Solution:**

1. **Understand the Classification of Bacteria:**
- Bacteria are classified based on their cell wall characteristics through a method called Gram staining. This classification divides bacteria into two main types: Gram-positive and Gram-negative.

2. **Identify Key Differences:**
- The primary difference between Gram-positive and Gram-negative bacteria lies in their cell wall structure.
- Gram-positive bacteria have a thick peptidoglycan layer, while Gram-negative bacteria have a thinner peptidoglycan layer and an additional outer membrane.

3. **Examine the Options:**
- The question provides four options:
- A. Peptidoglycan
- B. Lipopolysaccharide
- C. Teichoic acid
- D. None of the above

4. **Analyze Each Option:**
- **Option A: Peptidoglycan** - This is present in both Gram-positive and Gram-negative bacteria, so it cannot be the correct answer.
- **Option B: Lipopolysaccharide** - This component is found in the outer membrane of Gram-negative bacteria only, thus it is also incorrect.
- **Option C: Teichoic acid** - This is a unique component found in the cell walls of Gram-positive bacteria, making it the correct answer.
- **Option D: None of the above** - Since we have identified Teichoic acid as the correct answer, this option is incorrect.

5. **Conclusion:**
- The component that occurs in the cell walls of Gram-positive bacteria only is **Teichoic acid**.

**Final Answer: Teichoic acid**

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