Question

The phospholipid molecule has a head and two tails. The tails are found
A. At the surface of the membrane.
B. In the interior of the membrane
C. Spanning the membrane.
D. Where the environment is hydrophilic.

Answer 1

Hint:-The membrane which is responsible for delimiting the cells as well as the cellular organelles from its external environment and helps to remain separate from each other is known as the plasma membrane. The plasma membrane bears three major components. These are lipid, protein, and traces of carbohydrates.

Complete step-by-step solution:-Lipid comprises 50% of membrane mass. It is responsible for providing the basic structure of the membrane. There are three types of proteins located in the plasma membrane. These are phospholipid, glycolipid, and cholesterol. Phospholipid molecules are a type of lipid that bears a head and two tails. The Head comprises a phosphate group which makes it polar and water-loving or hydrophilic. Two tails of phospholipids are nonpolar and hydrophobic as it comes from fatty acids.
Phospholipids are found in the interior of the cell membrane and the membrane proteins are located on the surface of the membrane. The association of protein and lipid layers is maintained by the electrostatic interaction between the charged amino acid side chain of the protein and the polar end of the lipid head. The water-soluble molecules are not capable of passing the hydrophobic layer of the phospholipids.


Correct Answer: Option B. In the interior of the membrane.

Note:-
Phospholipid creates the bilayer structure of the plasma membrane. The major functions of the phospholipids are the creation of a barrier to the ions and other molecules from entering the cell. It is also responsible for entering certain components like oxygen, carbon dioxide into the cell. The molecules which can dissolve in the fat are capable of passing through the phospholipids.