Sorry i can only write the importance

Plasma membrane is also known as cell membrane. In plants it protects the cell wall and also protects the internal components of the cell. It gives shape and size to the cell.
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Plasma membrane is the thin outer covering present in all cells. It keeps the interior region separate from external environment and gives different identity to the cell organelles. Its thickness is 70A. It is made up of lipid (fats produced by smooth endoplasmic reticulum) having integrated protein molecules in it. It is selectively permeable. It si flexible because the organisation of membrane is not fixed
Functions :
To provide the shape to the cell
2. to maintain homeostasis 
3. To protect the cell