Can cholesterol form micelles and bilayers?

Can cholesterol form micelles and bilayers?
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Answer :

Cholesterol does not form micelles because it is not sufficiently amphiphilic (even though it does have an OH group) and its flat, rigid, fused-ring structure gives a solid rather than a liquid hydrocarbon phase at physiological temperatures. Such fluidity is required for micelle formation. However, cholesterol can form mixed micelles with amphiphilic lipids, and it enters monolayers as well where it constitutes ∼25% of the mass of the lipid bilayer in the plasma membranes of mammalian cells. 
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