They are made of a hydrocarbon chain that terminates with a carboxylic acid group; this arrangement confers the molecule with a polar, hydrophilic end, and a nonpolar, hydrophobic end that is insoluble in water.
De består af en carbonhydrid-kæde, der slutter i en carboxylsyre-gruppe; dette arrangement giver molekylet en polær, hydrofil ende, og en ikke-polær, hydrofob end, der er uopløselig i vand.