-Aqsa, Subject Matter Expert at Edumarz.
Solution: Plasma membrane or cell membrane is a living membrane that surrounds the cell and is situated inside the cell wall. It is similar to the cell membranes of all other organisms. It is composed mainly of phospholipids and proteins. A plasma membrane is a phospholipid bilayer in which phospholipid molecules are arranged in two parallel rows. The phospholipid molecule contains a polar head and non-polar tail. The polar head is composed of a phosphate group and glycerol.
Plasma membrane plays an important role in keeping the cell contents safe. It acts as a semi-permeable membrane, allowing only selected molecules to enter and leave the cell. Hence, if the plasma membrane breaks or ruptures, the molecules will move freely in and out of the cell disturbing the osmolarity leading to cell death.