Which of the following is the most important monomer component of the chitinous exoskeleton of arthropods ?

Options

A. N-acetyl glucosamine
B. Taurocholic acid
C. Hyaluronic acid
D. D - glucosamine

Answer

To solve the question regarding the most important monomer component of the chitinous exoskeleton of arthropods, we will analyze each of the options provided.

### Step-by-Step Solution:

1. **Understanding Chitin**:
- Chitin is a polysaccharide that forms a significant part of the exoskeleton of arthropods. It is crucial to identify its monomer components.

2. **Analyzing the Options**:
- **Option A: N-acetylglucosamine**:
- This is a derivative of glucose and is indeed the primary monomer that makes up chitin. Chitin is a polymer composed of repeating units of N-acetylglucosamine.
- **Option B: Taurocolic Acid**:
- This is a bile acid involved in fat emulsification and is not related to the structure of chitin. Therefore, this option is incorrect.
- **Option C: Hyaluronic Acid**:
- This is a glycosaminoglycan found in connective tissues, and it primarily functions in retaining water. It is not a component of chitin, making this option incorrect.
- **Option D: D-Glucosamine**:
- While D-glucosamine is an amino sugar and a precursor in the biosynthesis of various biomolecules, it is not the primary monomer of chitin. Thus, this option is also incorrect.

3. **Conclusion**:
- After analyzing all the options, the most important monomer component of the chitinous exoskeleton of arthropods is **N-acetylglucosamine**.

### Final Answer:
The correct answer is **N-acetylglucosamine**.

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