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:2/13/2017)... WASHINGTON , Feb. 13, 2017 Former ... U.S. Senate Judiciary Committee, Janice Kephart of ... regarding President Donald Trump,s "Executive Order: Protecting ... States" (Jan. 27, 2017):  "As President Trump,s ... 9th Circuit has now essentially banned the travel ban, ...
(Date:2/9/2017)... , Feb. 9, 2017 The biomass boiler ... of the biomass boiler market globally in terms of ... biomass boilers. The market for biomass boilers has been ... end-user, application, and country/region. The market based on feedstock ... forest residues, biogas & energy crops, urban residues, and ...
(Date:2/8/2017)...  Aware, Inc. (NASDAQ: AWRE ), a leading ... for its quarter and year ended December 31, 2016. ... $3.9 million compared to $6.9 million in the same quarter ... was $0.6 million compared to $2.6 million in the fourth ... 2016 was $0.5 million, or $0.02 per diluted share, which ...
Breaking Biology News(10 mins):
Other biology definition