Detailed Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: The formation of these compounds shows both a fast and slow relaxation phase, which lead to Aniansson and Wall's stepwise association-dissociation equilibrium model for their formation. Armstrong and Henry developed an HPLC variant that uses them, which analyzes proteins in biological fluids. Milk clotting results from casein forming these structures. One of their properties is determined using steady-state fluorescence quenching; that value is the number of molecules present in one of these structures at their critical concentration, known as the aggregation number. They only form above the Krafft temperature, and inverted ones form in organic solvents and have heads pointed inwards. They are the basis for the action of detergents, and are formed from surfactants. Similar to liposomes, for 10 points, name these spherical structures formed from amphipathic molecules, which have their hydrophobic tails pointing in and heads pointing out.
A:
Science