Among the following, one of them is not the correct match

Options

A. Silk (polyamide)
B. Indigo (azo dye)
C. Lipase (ester)
D. Keratin (protein)

Answer

To solve the question, we need to analyze each of the given matches and determine which one is incorrect. The options provided are:

1. Silk - Polyamide
2. Indigo - Azurdye
3. Lipase - Ester
4. Keratin - Protein

Let's evaluate each match step by step.

### Step 1: Analyze Silk - Polyamide
- Silk is a natural fiber composed of fibroin, which is an insoluble protein.
- Proteins are made up of amino acids linked by amide bonds.
- Since silk contains these amide bonds, it is classified as a polyamide.
- **Conclusion**: This match is correct.

**Hint**: Remember that polyamides are polymers formed from the reaction of diamines and dicarboxylic acids, and proteins can be considered polyamides due to their amide bonds.

### Step 2: Analyze Indigo - Azurdye
- Indigo is a dye with the chemical formula C16H10N2O2.
- Azurdyes are characterized by the presence of an -N=N- (azo) functional group, typically with aryl groups.
- Indigo does not contain this -N=N- functional group; instead, it has a different structure.
- **Conclusion**: This match is incorrect.

**Hint**: Look for the specific functional groups that define azurdyes, such as the azo group, to differentiate them from other types of dyes.

### Step 3: Analyze Lipase - Ester
- Lipase is an enzyme that helps in the digestion of fats.
- It is a type of protein that catalyzes the hydrolysis of esters, particularly triglycerides.
- While lipase acts on esters, it is itself not classified as an ester.
- **Conclusion**: This match is incorrect.

**Hint**: Understand the difference between enzymes (like lipase) and the substrates they act upon (like esters).

### Step 4: Analyze Keratin - Protein
- Keratin is a fibrous structural protein found in hair, nails, and skin.
- It is indeed classified as a protein due to its amino acid composition and structure.
- **Conclusion**: This match is correct.

**Hint**: Recall that keratin is a type of structural protein, which is essential in various biological structures.

### Final Conclusion
After analyzing all the matches, we find that the incorrect match is:

- Indigo - Azurdye (This is the incorrect match).

Thus, the answer to the question is that the incorrect match is **Option 2: Indigo - Azurdye**.