Phospholipids have unique properties which determine the isolation of the cytoplasm. They are amphipathic compounds having hydrophobic hydrocarbon chains (tails) and a hydrophilic head group in a single molecule. When an amphipathic compound is mixed with Water, the hydrophilic heads and water interact with each other and the hydrophobic tails do so in such a way that the molecules form micelles or liposomes (Figure 2.10). Because of this property, a damaged cytoplasmic membrane can restore its structure spontaneously, and when the cells are broken the membrane forms smaller vesicles (Figure 2.1 '1). When cells are broken with physical methods such as sonication or the French press, inside-out Vesicles are formed, While right-side- out Vesicles are formed when the protoplast is osmotically lyzed after the cell wall is removed using enzymes. Vesicles are a useful tool to study membranes without the interference of cytosolic activities. Phospholipid forms both inner and outer leaflets of the cytoplasmic membrane, but the membrane is asymmetrical due to proteins present in the membrane. The phospholipid bilayer membrane is permeable to hydrophobic solutes and water but not to charged solutes and polymers. Membrane proteins transport these in and out of the cell. Though water can diffuse through the membrane, the diffusion rate is too low