Which substance of saliva destroy harmful bacteria

Options

A. Cerumin
B. Chyme
C. Lysozyme
D. Secret

Answer

**Step-by-Step Solution:**

1. **Understanding Saliva**: Saliva is an extracellular fluid produced by the salivary glands in the mouth. It contains various components including water, mucus, white blood cells, enzymes, epithelial cells, and antimicrobial agents.

2. **Identifying the Options**: The question asks which substance in saliva destroys harmful bacteria. The options provided include cerumen, chyme, lysozyme, and secretin.

3. **Analyzing Each Option**:
- **Cerumen**: This is a waxy substance produced by ceruminous glands in the auditory canal. It is not found in saliva, so this option is incorrect.
- **Chyme**: This is an acidic fluid found in the stomach that consists of gastric juice and partially digested food. It is not a component of saliva, making this option incorrect as well.
- **Lysozyme**: This is an enzyme that plays a crucial role in innate immunity. It has antimicrobial properties and works by breaking down the cell walls of bacteria, effectively killing them. Lysozyme is present in saliva, making this the correct option.
- **Secretin**: This is a hormone released by the duodenum in response to acidity. It stimulates the secretion of digestive juices but is not found in saliva, so this option is also incorrect.

4. **Conclusion**: The substance in saliva that destroys harmful bacteria is lysozyme.

**Final Answer**: The substance of saliva that destroys harmful bacteria is **lysozyme**.

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