Final answer:
Surfactants and fatty amphiphiles share all the listed characteristics: surface activity, formation of micelles, and formation of liquid crystals. As such, the correct answer is 4) All of the above.
Step-by-step explanation:
The characteristics shared by surfactants and fatty amphiphiles include surface activity, the formation of micelles, and the ability to form liquid crystals. Therefore, the correct answer to what characteristics are shared by surfactants and fatty amphiphiles is 4) All of the above.
Surfactants, like soaps and detergents, reduce surface tension by disrupting the intermolecular attractions between adjacent water molecules. They can interact with polar and nonpolar substances, creating emulsions and effectively decreasing the surface tension of water. Fatty amphiphiles, such as phospholipids, are crucial components of cell membranes and display similar behavior in water. They have a polar, hydrophilic head and two hydrophobic fatty acid tails, leading them to arrange themselves in various structures, including micelles and bilayers, when in an aqueous environment.
When these molecules interact with water, they spontaneously form organized structures like micelles—where hydrophobic tails are shielded from water by the hydrophilic heads—and bilayers, which form the basic structure of cell membranes. These bilayers can exhibit liquid crystalline properties under certain conditions. Both surfactants and fatty amphiphiles demonstrate the unique ability to form micelles, which serve as a means to isolate hydrophobic molecules in an aqueous environment, a principle that is vital in biological systems and various industrial applications.