Q. Recognizes true statements of cholesterol and its fluidity.

1. Cholesterol decreases membrane fluidity in areas called rafts that include large amounts of sphingolipids and cholesterol.

2. Cholesterol inhibits crystallization that would else occur in membranes rich in unsaturated fatty acids.

3. Cholesterol is usually buried in a bilayer, with its planar rings oriented toward the solvent and its hydroxyl group aligned with the fatty acid tails of the bilayer.

4. Cholesterol increases membrane fluidity that otherwise contains mainly long chain saturated fatty acids