Question

When ________ are exposed to water they arrange themselves into a two layered sheet. They are therefore important components of all membranes found in living organisms.

Answer 1

Phospholipids form a bilayer structure when exposed to water, with hydrophilic heads facing the water and hydrophobic tails facing each other, creating a vital component of biological membranes in cells.

Step-by-step explanation:

When phospholipids are exposed to water, they arrange themselves into a two-layered sheet, which is essential for forming biological membranes in living organisms. This arrangement happens because phospholipids have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. When in water, the hydrophilic heads face outward towards the water, while the hydrophobic tails face inward, away from the water, thereby creating a bilayer. This bilayer structure is a fundamental characteristic of plasma membranes, which encapsulate cells and compartmentalize the internal environment from the external aqueous environment.