Take a living tissue, grind it in trichloroacetic acid using pestle and mortal, 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 components of the acid-insoluble fraction obtained from grinding living tissue in trichloroacetic acid, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Process**:
- When living tissue is ground in trichloroacetic acid (TCA), it helps to extract various biomolecules. TCA is a strong acid that precipitates proteins and other macromolecules.

2. **Separation of Fractions**:
- After grinding, the mixture is strained to separate the contents into two fractions:
- **Acid-soluble fraction**: This fraction contains molecules that remain dissolved in the acid.
- **Acid-insoluble fraction**: This fraction contains the molecules that precipitate out and do not dissolve in the acid.

3. **Components of Acid-Insoluble Fraction**:
- The acid-insoluble fraction typically contains:
- Proteins
- Polysaccharides (complex sugars)
- Nucleic acids (DNA and RNA)
- Lipids

4. **Identifying What is NOT Present**:
- The question asks for components that are NOT present in the acid-insoluble fraction. Based on the information gathered, the acid-insoluble fraction does not contain secondary metabolites such as:
- Flavonoids
- Alkaloids

5. **Conclusion**:
- Therefore, the correct answer to the question is that the acid-insoluble fraction does not contain flavonoids and alkaloids, which are secondary metabolites.

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