Proteins are broken down into amino acids in -

Options

A. Buccal cavity
B. Stomach
C. Intestine
D. Rectum

Answer

**Step-by-Step Solution:**

1. **Understanding Protein Digestion**: Proteins are large molecules that need to be broken down into smaller units called amino acids for absorption and utilization by the body.

2. **Analyzing the Options**:
- **Option 1: Buccal Cavity**: In the buccal cavity, the primary digestion that occurs is of starch due to the action of salivary amylase. Proteins are not digested here, making this option incorrect.

- **Option 2: Stomach**: The stomach does initiate protein digestion through the action of gastric juices, particularly pepsin, which breaks proteins down into smaller polypeptides (peptones). However, this process does not completely convert proteins into amino acids. Thus, this option is also incorrect.

- **Option 3: Intestine**: The small intestine is where the majority of protein digestion occurs. Here, enzymes such as trypsin and chymotrypsin further break down the polypeptides into amino acids. Therefore, this option is correct.

- **Option 4: Rectum**: The rectum is part of the digestive tract where no digestion occurs; it is primarily involved in the storage of waste. Hence, this option is incorrect.

3. **Conclusion**: After evaluating all options, the correct answer is that proteins are broken down into amino acids in the intestine.

**Final Answer**: Option 3: Intestine.

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