Question

Which of the following is an amphipathic molecule in the plasma membrane
(a) Protein
(b) Carbohydrates
(c) Phospholipids
(d) All of the above

Answer 1

Hint: The biological molecule which contains both hydrophilic and hydrophobic properties, used to build biological membranes of a cell.

Complete step by step answer:
The chemical compounds that have both polar and nonpolar regions giving both hydrophilic and hydrophobic properties are called amphipathic molecules. The cell uses amphipathic molecules to build biological membranes. The amphipathic molecule has several hydrophilic and hydrophobic parts. Some of the examples of amphipathic molecules include bile salts, surfactants, and phospholipids.
So, the correct answer is, ‘(c) Phospholipids’.

Additional information:
- The lipophile is usually a hydrocarbon, consisting of carbon and hydrogen atoms. Lipophilic portions are non- polar molecules and they are hydrophobic. The hydrophilic group can be charged or uncharged. Charged groups may be a cationic (positively charged) example, ammonium groups. Other charged groups are anionic, such as carboxylates, phosphates, sulfates, and sulfonates.
Examples of polar, uncharged groups include alcohol.
- Amphipathic molecules may partially dissolve in both water and nonpolar solvents. When amphipathic molecules are mixed in a mixture containing water and organic solvents, they divide the two phases.
- Amphipathic molecules have several important biological roles.
- They are the primary component of the lipid bilayers that form membranes.
- To alter or disturb a membrane, the cell uses amphipathic compounds called 'pepducins, which push their hydrophobic region into the membrane and expose the hydrophilic hydrocarbon tails to the aqueous environment. The body uses amphipathic molecules for digestion.
- Amphipathic molecules are also important in the immune response.
- Antifungal and antibacterial properties are shown by Amphipathic antimicrobial peptides.

Note:
- Amphipathic molecules are also known as amphiphilic molecules.
- The commercial use of amphipathic molecules include
Used in the preparation of cleansing soaps and detergents
Used to make local anesthetics
Used to deliver nutrients or drugs.