Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A micelle is an aggregate of surfactant molecules dispersed in a liquid colloid, forming a spherical structure. In aqueous solutions, the hydrophobic tails face inward while the hydrophilic heads face outward.
5 Must Know Facts For Your Next Test
Micelles are formed when the concentration of surfactant exceeds the critical micelle concentration (CMC).
In biological systems, micelles facilitate the absorption of lipids and fat-soluble vitamins in the intestines.
Micelles play a crucial role in emulsification, aiding in the digestion and transport of lipids.
Bile salts form micelles to solubilize cholesterol and other lipids for excretion or absorption.
The size and shape of micelles can vary depending on the type and concentration of surfactant molecules.
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Related terms
Surfactant: A substance that reduces surface tension between two liquids or a liquid and a solid.
Emulsification: The process of mixing two immiscible liquids to form a stable dispersion.
Bile Salts: Molecules produced by the liver that aid in digestion by emulsifying fats into smaller droplets.