Keratin and chitin are chemically

Options

A. carbohydrates& are functionally similar
B. carbohydrates but functionally different
C. proteins and functionally similar
D. different but functionally similar.

Answer

To answer the question "Keratin and chitin are chemically," we need to analyze the chemical nature and functional similarities of both keratin and chitin.

### Step-by-Step Solution:

1. **Identify Keratin**:
- Keratin is a fibrous protein that is primarily found in the outer layer of the skin, hair, and nails. It is a structural protein that provides protection and strength.

2. **Identify Chitin**:
- Chitin is a modified polysaccharide. It is not a protein but rather a carbohydrate derivative. Chitin is found in the cell walls of fungi and the exoskeletons of arthropods (such as insects and crustaceans).

3. **Chemical Composition**:
- Keratin is composed of amino acids, which are the building blocks of proteins. It has a complex structure that includes alpha-helices and beta-sheets, contributing to its fibrous nature.
- Chitin, on the other hand, is made up of N-acetylglucosamine units, which are linked by β(1→4) glycosidic bonds. This structure gives chitin its rigidity and strength.

4. **Functional Similarities**:
- Despite their different chemical compositions, both keratin and chitin serve protective functions. Keratin protects cells in the skin and forms a barrier against environmental damage, while chitin provides structural support and protection in fungi and arthropods.

5. **Conclusion**:
- Therefore, keratin and chitin are chemically different (as keratin is a protein and chitin is a carbohydrate), but they are functionally similar because both provide protection.

### Final Answer:
Keratin and chitin are chemically different (keratin is a protein, and chitin is a modified polysaccharide), but they are functionally similar as both provide protection.

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