Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Amphiphile

Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_67-3

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...

Keywords

Carbon Atom Living Cell Carboxylic Acid Bioorganic Chemistry Lipid Bilayer 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Department of ChemistryUC Santa CruzSanta CruzUSA