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Plasma Membrane

The plasma membrane in Eukaryotes separates the cell's cytoplasm from the surrounding extracellular environment. The plasma membrane is a lipid bilayer, a double sheet of phospholipids.

Plasma Membrane

Phospholipid are remarkable for being hydrophilic (blue head) and hydrophobic (yellow tail). The hydrophobic tail is formed by long carbohydrate chains of lipid acids while the hydrophilic head bears a phosphate whose polarity attracts other polar molecules, most abundantly water. At the other end, the hydrophobic sites tend to congregate thereby forming stable structures impermeable for polar molecules.

A similar membrane insulates compartments within a cell, organelles, and there is a perpetual exchange between these membranes with endocytosis and exocytosis describing the route from and to the cell membrane.

Tags: Anatomy Cell

Categories: Biochemistry


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