Decoding Cholesterol's Influence on Cell Membrane Function & Fluidity

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Cholesterol plays a crucial role in regulating membrane fluidity in cells. The effects of cholesterol on membrane fluidity depend on the lipid bilayer's temperature and composition.

At high temperatures:

Cholesterol acts as a fluidity buffer: In high-temperature environments, cholesterol decreases the membrane's fluidity. It fills the gaps between the phospholipids and reduces their movement, making the membrane less fluid and more rigid. This prevents the membrane from becoming too fluid or "leaky" under high-temperature conditions.

At low temperatures:

Cholesterol enhances membrane fluidity: In low-temperature environments, cholesterol is, oppositely, a fluidity buffer. It prevents the membrane from becoming too rigid and maintains its fluidity. Cholesterol inserts itself between phospholipids, preventing them from packing too closely together and forming a solid-like structure. This helps to maintain the proper fluidity and flexibility of the membrane.