Question

Explain why phospholipids spontaneously form a bilayer when mixed with water? 1. Because the polar tails come together in the inside of the membrane; 2. because the polar head groups come together; 3. because they have one end that is polar and another that is non-polar

Answer 1

The correct answer is 3 that is because they have one end that is Pilar and another that is non polar. Polar end is phosphate group and it Hydrophillic, and the non polar end is fatty acid chains and those are hydrophobic. So, when phospholipids when mixed with water hydrophobic groups tend to go away from the water and hence they aggregate together and Hydrophillic group is attached to water and they remain outside towards the water. This is the reason they form bilayer so that non polar tails remain inside and polar heads remain outside.