Lipids are insoluble in water, because lipids molecules are

Options

A. hydrophilic
B. hydrophobic
C. neutral
D. Zwitter ions

Explanation

### Step-by-Step Solution:

1. **Understanding Lipids**: Lipids are a class of biomolecules that include fats, oils, and waxes. They are primarily composed of fatty acids and glycerol.

2. **Structure of Lipids**: Lipids are formed through a process called esterification, where fatty acids are attached to a glycerol molecule. This results in the formation of an ester bond.

3. **Hydrophobic Nature of Fatty Acids**: The key reason lipids are insoluble in water is due to the hydrophobic nature of fatty acids. Fatty acids have long hydrocarbon chains that do not interact favorably with water molecules.

4. **Hydrophilic vs. Hydrophobic**:
- **Hydrophilic** means "water-loving," which refers to molecules that can interact with water, often forming hydrogen bonds.
- **Hydrophobic** means "water-repelling," which refers to molecules that do not interact with water and do not form hydrogen bonds.

5. **Solubility in Organic Solvents**: While lipids are insoluble in water, they are soluble in organic solvents such as ether, acetone, and ethyl alcohol. This is because organic solvents can interact with the non-polar regions of lipid molecules.

6. **Conclusion**: Therefore, lipids are insoluble in water because they are composed of hydrophobic fatty acids that do not form hydrogen bonds with water.

### Final Answer:
Lipids are insoluble in water because lipid molecules are hydrophobic.

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