Phosphatidylcholine is an amphipathic molecule, consisting of a hydrophilic head and a hydrophobic tail. It is a type of phospholipid with a choline group inserted into the head. Phosphatidylcholine is an important component of biological membranes and can be easily extracted from a variety of sources, such as egg yolks and soybeans, often using hexane as the reagent. Phosphatidylcholine is also an important component of brown fat in animal and plant tissues.