Page 531 - AWSAR 2.0

Scramblases – Guardians of the Cell
Mr. Santoshkumar Palanirajan*
Email: santoshrajan16@gmail.com
|| 507
Cells are the basic unit of life. Each cell has a membrane protecting from external harm similar to the walls of our
home. Cell membranes are made up of several forms of lipids and proteins. Among them, phospholipids are similar to bricks of the wall, which stick to each other and self-associate to form a barrier. The membranes define the boundary of a cell and help to keep its contents intact, and at the same time remain fluidic. If not for phospholipids, the membranes would become rigid like a brick wall and our cells would be firm-brittle.
The cell boundary is composed of phospholipids, which, unlike bricks, are classified into two categories based on their charge. The phospholipids form a two-tier defense system by forming a bilayer around
the cell. The outer layer or primary defense is mainly composed of neutral phospholipids, and the inner layer or the second tier of the boundary is majorly composed of charged lipids. The charged phospholipids face the residents of the home and stay intact, while the neutral phospholipids are exposed to the streets and act as the primary layer of defense. The two layers together form the boundary of the cells and help them remain safe and sound.
These membranes are flexible and fluidic like a pool of water with several floaters called as membrane proteins. These floaters are the life jackets for any cell as they act as a messenger in receiving and transmitting the signal from one cell to the other or act as guards by frisking and letting in only essential molecules such as calcium, sodium, potassium, and several
* Mr. Santoshkumar Palanirajan, PhD Scholar from Indian Institute of Technology, Madras, is pursuing his research on “Biochemical Characterization of Human Phospholipid Scramblases”. His popular science story entitled “Scramblases- Guardians of the Cell” has been selected for AWSAR Award.