Which of the following is digested by saliva?

Options

A. glucose
B. starch
C. cellulose
D. sucrose

Answer

**Step-by-Step Solution:**

1. **Understanding Saliva**: Saliva is a digestive fluid secreted by salivary glands in the mouth. It plays a crucial role in the digestion of food by moistening it and containing digestive enzymes.

2. **Identifying Digestive Enzymes in Saliva**: The main digestive enzyme present in saliva is amylase. Amylase is responsible for breaking down starch into simpler sugars.

3. **Analyzing the Options**:
- **Glucose**: This is a monosaccharide and does not require digestion.
- **Starch**: This is a polysaccharide and is digested by saliva (specifically by amylase).
- **Cellulose**: This is a complex carbohydrate found in plant cell walls, and humans cannot digest it.
- **Sucrose**: This is a disaccharide (composed of glucose and fructose) and is not directly digested by saliva.

4. **Conclusion**: Among the given options, starch is the only substance that is digested by saliva.

**Final Answer**: Starch is digested by saliva.

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