Digestion of proteins begins in the _______, and digestion of polysaccharides begins in the ______.

Options

A. Mouth.......stomach
B. Stomach.....small intestine
C. Stomach.....mouth
D. Stomach....stomach

Answer

To answer the question, "Digestion of proteins begins in the _______, and digestion of polysaccharides begins in the ______," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Digestion**:
- Digestion is the process of breaking down biomacromolecules (like proteins and carbohydrates) into smaller units that can be absorbed by the body.

2. **Identifying Where Protein Digestion Begins**:
- Protein digestion primarily occurs in the stomach. The enzyme responsible for this process is pepsin, which breaks down proteins into smaller peptides. Pepsin is secreted in an inactive form (pepsinogen) and is activated in the acidic environment of the stomach.

3. **Identifying Where Polysaccharide Digestion Begins**:
- The digestion of polysaccharides (complex carbohydrates) begins in the mouth. The enzyme that initiates this process is salivary amylase, which breaks down starches into simpler sugars like maltose.

4. **Combining the Information**:
- From the above points, we conclude that:
- Digestion of proteins begins in the **stomach**.
- Digestion of polysaccharides begins in the **mouth**.

5. **Final Answer**:
- Therefore, the complete answer is: "Digestion of proteins begins in the **stomach**, and digestion of polysaccharides begins in the **mouth**."