Paper 3 · November 2023 · Cell Structure and Membranes
In an aqueous environment, phospholipids spontaneously form a bilayer with
Ano consistent arrangement, since phospholipids distribute randomly through the membrane.
Bhydrophilic heads facing each other in the centre and hydrophobic tails facing the water on both sides.
Chydrophobic tails facing each other in the centre and hydrophilic heads facing the water on both sides.
Dhydrophobic tails facing the water on one side only and hydrophilic heads facing the water on the other.
Explanation
The hydrophobic tails avoid water by facing inward toward each other, while the hydrophilic heads face outward into the water on each side, giving the bilayer its stability and its role as a hydrophobic barrier.
Derived from ZIMSEC Biology 6030/3 Paper 3, November 2023, Q1