How does cholesterol affect membrane fluidity?
Cholesterol acts as a bidirectional regulator of membrane fluidity because at high temperatures, it stabilizes the membrane and raises its melting point, whereas at low temperatures it intercalates between the phospholipids and prevents them from clustering together and stiffening.
What is a lipid monolayer?
Lipid monolayers are a model system that mimics the outer leaflet of cell membranes [83]. Lipid membranes can undergo transitions changing the lateral order of the lipid molecules and the order parameter of the hydrocarbon chains. The compression of a lipid monolayer allows exploring these changes in the lipid packing.
What does the phospholipid bilayer do?
Phospholipid bilayers are critical components of cell membranes. The lipid bilayer acts as a barrier to the passage of molecules and ions into and out of the cell. However, an important function of the cell membrane is to allow selective passage of certain substances into and out of cells.
What can pass through the phospholipid bilayer?
Gases, hydrophobic molecules, and small polar uncharged molecules can diffuse through phospholipid bilayers.
Does cholesterol decrease membrane fluidity?
The role of cholesterol in bilayer and monolayer lipid membranes has been of great interest. On the biophysical front, cholesterol significantly increases the order of the lipid packing, lowers the membrane permeability, and maintains membrane fluidity by forming liquid-ordered–phase lipid rafts.
Does cholesterol make membrane more or less fluid?
Depending on the temperature, cholesterol has distinct effects on membrane fluidity. At high temperatures, cholesterol interferes with the movement of the phospholipid fatty acid chains, making the outer part of the membrane less fluid and reducing its permeability to small molecules.
What is a cell monolayer?
Monolayers are frequently encountered in biology. In cell culture a monolayer refers to a layer of cells in which no cell is growing on top of another, but all are growing side by side and often touching each other on the same growth surface.
What are monolayer associated proteins?
Monolayer-associated proteins are proteins that situated within the cell; or the cytosol. It interact with the inner layer of the lipid bilayer.