Take a living tissue, grind it in trichloroacetic acid using pestle and mortar, and then strain it, you would obtain two fractions : acid-soluble and acid-insoluble fraction. Acid-insoluble fraction does not contain

Options

A. polysaccharides
B. nucleic acids
C. lipids
D. flavonoids and alkaloids.

Explanation

To solve the question regarding the acid-insoluble fraction obtained from grinding living tissue in trichloroacetic acid, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Experiment**:
- We start with a living tissue sample.
- The tissue is ground in trichloroacetic acid using a pestle and mortar.

2. **Grinding the Tissue**:
- The grinding process helps to break down the tissue and allows the trichloroacetic acid to interact with the cellular components.

3. **Straining the Mixture**:
- After grinding, the mixture is strained to separate the liquid from the solid components. This results in two fractions:
- **Acid-soluble fraction**: This fraction contains smaller molecules that dissolve in the acid.
- **Acid-insoluble fraction**: This fraction contains larger molecules or components that do not dissolve in the acid.

4. **Identifying the Components**:
- The acid-soluble fraction typically includes:
- Carbohydrates
- Proteins
- Nucleic acids
- Lipids
- The acid-insoluble fraction, on the other hand, does not contain certain compounds.

5. **Determining What the Acid-Insoluble Fraction Lacks**:
- The acid-insoluble fraction does not contain:
- Flavonoids
- Alkaloids
- It may contain polysaccharides, nucleic acids, and lipids, but the question specifically asks what it does not contain.

6. **Conclusion**:
- Therefore, the acid-insoluble fraction does not contain flavonoids and alkaloids.

### Final Answer:
The acid-insoluble fraction does not contain flavonoids and alkaloids.