Navigation Links
Lipid bilayer


A DPPC bilayer simulation
Color scheme: PO4 = green, N(CH3)3 = violet, water = blue, terminal CH3 = yellow, O = red, glycol C = brown, chain C = grey

In biology and chemistry, a lipid bilayer is a membrane or zone of a membrane composed only of lipid molecules. The lipid bilayer is the foundation of all biological membranes, and is a prerequisite of cell-based life.

Within a critical range of concentrations, certain kinds of lipids alone in a test tube of water will self-organize to form a "bilayer". The bilayer is composed of two opposing layers of lipid molecules arranged so that their hydrocarbon tails face one another to form the oily bilayer core, while their electrically charged or polar heads face the watery or "aqueous" solutions on either side of the membrane.

Because of the oily core, a pure lipid bilayer is permeable to small hydrophobic solutes but has only a very low permeability barrier to inorganic ions and other hydrophilic molecules. Water itself is an exception to this rule, and crosses freely.

Other self-organizing structures that lipids assume, depending on their concentration and type, include micelles, monolayers and vesicles. Cholesterol molecules in the bilayer assist in regulating fluidity.

See also


'"/>


(Date:6/23/2017)... ARMONK, N.Y. and ITHACA, N.Y. ... IBM ) and Cornell University, a leader in dairy ... combined with bioinformatics designed to help reduce the chances ... breaches. With the onset of this dairy project, Cornell ... the Consortium for Sequencing the Food Supply Chain, a ...
(Date:5/16/2017)... TEANECK, N.J. , May 16, 2017  Veratad ... leading provider of online age and identity verification solutions, ... the K(NO)W Identity Conference 2017, May 15 thru May ... Ronald Regan Building and International Trade Center. ... across the globe and in today,s quickly evolving digital ...
(Date:4/24/2017)... , April 24, 2017 ... and partner with  Identity Strategy Partners, LLP (IdSP) ... "With or without President Trump,s March 6, 2017 ... Terrorist Entry , refugee vetting can be instilled with ... resettlement. (Right now, all refugee applications are suspended ...
Breaking Biology News(10 mins):
Other biology definition