Synonyms
Definition
An amphiphile is a molecule having both a hydrophobic nonpolar group and a hydrophilic polar group. The nonpolar hydrophobic portion of the molecule is typically a hydrocarbon chain ranging from 10 to 20 or more carbon atoms in length, and the polar moiety can be a carboxylic acid, phosphate, sulfate, amine, or alcohol group, among other possibilities. Examples of amphiphiles are fatty acids, detergents, and all lipids including phospholipids and sterols. All amphiphiles are surface active and form monolayers at air-water interfaces. Some amphiphiles, particularly those with a single hydrocarbon chain, assemble into micellesin aqueous solutions. Other amphiphiles with two hydrocarbon chains, for instance, phospholipids, typically self-assemble into bilayer membranes that are the permeability barriers defining most forms of cellular life. Amphiphilic molecules resembling fatty acids are present in carbonaceous meteorites and are...
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2015 Springer-Verlag Berlin Heidelberg
About this entry
Cite this entry
Deamer, D. (2015). Amphiphile. In: Gargaud, M., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-44185-5_67
Download citation
DOI: https://doi.org/10.1007/978-3-662-44185-5_67
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-44184-8
Online ISBN: 978-3-662-44185-5
eBook Packages: Physics and AstronomyReference Module Physical and Materials ScienceReference Module Chemistry, Materials and Physics