Which of the following is not a function of membranous extensions like vesicles and tubules?

Options

A. Cell wall formation
B. Increase the surface area of the plasma membrane
C. Helps in protein synthesis
D. Helps in respiration

Answer

To solve the question "Which of the following is not a function of membranous extensions like vesicles and tubules?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Membranous Extensions**:
- Membranous extensions such as vesicles and tubules are structures formed by the membrane of cells. They play various roles in cellular processes.

2. **Analyzing Each Option**:
- **Option 1: Cell wall formation**:
- This option is incorrect as membranous extensions like vesicles and tubules do not participate in the formation of the cell wall. The cell wall is primarily formed by polysaccharides and proteins, not by vesicles or tubules.

- **Option 2: Increase the surface area of plasma membrane**:
- This option is correct. Membranous extensions such as mesosomes in bacteria do increase the surface area of the plasma membrane, which can aid in various cellular functions including respiration.

- **Option 3: Helps in protein synthesis**:
- This option is also correct. While vesicles can transport proteins, the actual synthesis of proteins occurs on the rough endoplasmic reticulum, which is a membranous structure but not a vesicle or tubule.

- **Option 4: Helps in respiration**:
- This option is correct as well. Membranous extensions like mesosomes in bacteria are involved in respiration by increasing the surface area for respiratory processes.

3. **Conclusion**:
- After analyzing all the options, the only function that is not associated with membranous extensions like vesicles and tubules is **cell wall formation**.

### Final Answer:
- The correct answer is **Option 1: Cell wall formation**.