Question

Phospholipid molecules of cell membrane possess
A. One polar head and polar tail
B. One non polar head and one non-polar tail
C. One polar head and two non-polar tails
D. One non polar head and two polar tails

Answer 1

Hint: The structure of the phospholipid molecule consist of a hydrophilic head and two hydrophobic tail. The hydrophobic molecules are non-polar and hydrophilic molecules are polar.

Step by step answer:A phospholipid is a type of lipid molecule which is the main component of the plasma membrane of the cell. Lipids are molecules that include fats, waxes, and some vitamins, among others. Each phospholipid molecule comprises two fatty acids, a phosphate group, and a glycerol molecule. The plasma membrane is also called the phospholipid bilayer because of two layers which comprise of orderly arranged phospholipid molecules.
A phospholipid molecule is made of a phosphate group head and two fatty acid tails attached at its base. Fatty acids are long chains comprising mostly hydrogen and carbon. The phosphate groups consist of a phosphorus molecule to the center with four oxygen molecules attached to it. These two components of the phospholipid molecule are connected with the help of glycerol.
They head of the phospholipid molecule is a hydrophilic molecule in nature. This means they favor bonding with water molecules whereas the fatty acid tails repel the bond formation with the water molecule. Hydrophilic molecules are polar molecules that are attracted to water molecules and dissolve in water easily. On the other hand, hydrophobic molecules are non-polar molecules, and due to which they do not disassociate in water.
Hence option C is correct

Note: The cell membrane acts as a selectively permeable membrane allowing only specific molecules of specific sizes. It allows water molecules but restricts the entry of fat and oil molecules. It only allows molecules of small size and restricts molecules like glucose to enter. This helps in maintaining a balance in the cell and prevent overload. It also provides a suitable environment within the cell and helps in cell signaling as well.