How does cholesterol affect cell membranes?

Cholesterol plays a critical role in maintaining the structural integrity and functionality of cell membranes. It inserts itself between the phospholipids in the bilayer, which contributes to the overall fluidity of the membrane. By doing this, cholesterol helps to prevent the fatty acid chains of the phospholipids from packing too closely together, allowing the membrane to remain flexible and stable across different temperatures.

This role is vital because if membranes were too fluid, they would not be able to retain their shape or contain the proteins and other molecules that are essential for cell signaling and transport. Conversely, if membranes were too rigid, they would not allow for the necessary movement of materials in and out of the cell, which is crucial for maintaining homeostasis. Therefore, cholesterol’s ability to help maintain both fluidity and stability is essential for the proper functioning of cells.