Which one forms chemical barrier for infections

Options

A. Isozyme
B. Coughing
C. Lysozyme
D. Lysosome

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which option forms a chemical barrier against infections. This means we need to identify a substance that helps to prevent or fight off infections through chemical means.

2. **Analyzing the Options**: The options provided are Isozyme, Caffeine, Lysozyme, and Lysosome. We need to evaluate each one to see if it serves as a chemical barrier.

3. **Defining Each Option**:
- **Isozyme**: These are different forms of an enzyme that catalyze the same reaction but may differ in structure. They do not specifically act as a barrier against infections.
- **Caffeine**: This is a stimulant found in coffee and tea. It does not have a role in forming a chemical barrier against infections.
- **Lysozyme**: This is an antibacterial enzyme that is part of the innate immune system. It is produced by humans and animals and is found in various secretions such as tears, saliva, and mucus.
- **Lysosome**: This is an organelle within cells that contains degradative enzymes. While it plays a role in breaking down waste, it is not a chemical barrier against infections.

4. **Identifying the Correct Answer**: Among the options, Lysozyme stands out as it is specifically known to have antibacterial properties and acts as a chemical barrier by breaking down bacterial cell walls, thus preventing infections.

5. **Conclusion**: The correct answer to the question is **Lysozyme**.