Would it be problematic for a cell if it's plasma membrane was inverted, with the phospholipid heads in the middle of the plasma membrane and the tails on the outside of the membrane? Why or why not?

Question

What will be an ideal response?

Answer 1

Yes, this would be very problematic for a cell. A phospholipid consists of a phosphate-containing head with two long hydrocarbon tails that are typically derived from fatty acids. Importantly, the tails are hydrophobic, but the highly polar phosphate group makes the head hydrophilic. The cell membrane consists of phospholipids arranged in two layers (lipid bilayer). The hydrophilic heads of one layer are dissolved in the cell's watery interior and the hydrophilic heads of the other layer are dissolved in the cell's fluid surroundings. All of the hydrophobic tails are sandwiched between the hydrophilic heads. This arrangement is crucial to maintaining a division between the cell and its external environment. Since the external environment and the internal environment of the cell are both water-based, the hydrophilic heads must for the outer lining of the plasma membrane and the hydrophobic heads must remain in the middle of the plasma membrane. If this arrangement was inverted, the plasma membrane would not form.