Plasma membrane of the cell is a living motile (fluid) structure having lipids, proteins and externally attached sugars. It has a number of functions such as providing shape to cell, acting as mechanical barrier between cell contents and environment, selective permeability, endocytosis (i.g., paenocytosis, phagocytosis), recognition, flow of information, passage of water, flow of external fluids by cilia or absorpiton of antirients by its microvilli.
The diverse functions of the plasma membrane are possible due to adpation of proteins to from channels, enzymes, carriers, receptors and their attachment to small carbohydrates (oligosaccharides).
Like proteins, every human being has to perform differenf functions in the human society. For example Muskan is daughter of her parents, sister of her brother, student of her school, a table tennis plater, a friend to several class fellows, a companion of her pet, a gardner in home garden, a helper to the mother, a caretaker of the grand parents, an active social worker, etc.
