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 made up of amino acids. The process of digestion breaks down proteins into their constituent amino acids, which can then be absorbed by the body.

2. **Identifying the Site of Digestion**:
- **Buccal Cavity**: The first option is the buccal cavity (mouth). In the mouth, the enzymes present (salivary amylase and lingual lipase) primarily digest carbohydrates and fats, not proteins. Therefore, this option is incorrect.

- **Stomach**: The second option is the stomach. The stomach does contain the enzyme pepsin, which begins the digestion of proteins. However, pepsin breaks down proteins into smaller peptides (not directly into amino acids). Thus, while some digestion occurs here, it does not complete the process to amino acids. This option is also incorrect.

- **Intestine**: The third option is the intestine. The small intestine is where the majority of protein digestion occurs. Pancreatic enzymes such as trypsin, chymotrypsin, and carboxypeptidase are secreted into the small intestine and continue the breakdown of proteins into smaller peptides and eventually into amino acids. This is where proteins are fully digested into amino acids, making this option correct.

3. **Conclusion**: The correct answer to the question "Proteins are broken down into amino acids in-" is the intestine (small intestine).

**Final Answer**: Proteins are broken down into amino acids in the intestine.

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