Question

What are amphipathic molecules?

Answer 1

Hint: Amphipathic molecules are also known as amphiphilic molecules. Cholesterol, detergents, and phospholipids are an example of amphipathic molecules.

Complete Answer:
- The chemical compounds which have at least one hydrophilic portion and one hydrophobic portion are called amphipathic molecules. They contain properties of both types.
- Most membrane lipids are amphipathic. The typical example is phospholipids found in the cell membrane. The hydrophilic region is also called the water-loving head and face outside. On the contrary, the hydrophobic region also called water-repelling ends has two tails of fatty acids.
- Hydrophobic tails usually face towards the center of the membrane. This makes the cell membrane a lipid bilayer. Another example is soap, which has a hydrophilic head and a hydrophobic tail, allowing it to dissolve in both water and oil.

Additional information: Based on polarity, the molecules can be classified as hydrophilic, lipophilic, and amphiphilic molecules.
- Hydrophilic molecules are those molecules which love water or that can be dissolved in water. These are ionic, polar covalent compounds. Starch is an example of a hydrophilic molecule. Cellulose fibers are hydrophilic because of the presence of -OH groups at their surfaces.
- The hydrophobic molecules are water or hydro-fearing molecules. They cannot be dissolved in water as such. Oil and fats are typical examples of hydrophobic.

Note: The prefix ‘Amphi’ means ‘both’. For example, amphibians, which can live in aquatic and terrestrial both types of habitat. Saturated hydrocarbons such as ethane, propane, butane is a good example of hydrophobic molecules.