Navigation Links
Biological membrane


A biological membrane or biomembrane is a membrane which acts as a barrier within or around a cell. It is a lipid bilayer, being composed of a double layer of lipid-class molecules, specifically phospholipids, with occasional proteins intertwined, some of which function as channels.

Such membranes typically define enclosed spaces or compartments in which cells may maintain a chemical or biochemical environment that differs from the outside. For example, the membrane around peroxisomes shields the rest of the cell from peroxides, and the plasma membrane separates a cell from its surrounding medium. Most organelles are defined by such membranes.

Probably the most important feature of a biomembrane is that it is a selectively permeable structure. This means that the size, charge and other chemical properties of the atoms and molecules attempting to cross it will determine whether they succeed to do so. Selective permeability is essential for effective separation of a cell or organelle from its surroundings.

If a particle is too large or otherwise unable to cross the membrane by itself, but is still needed by a cell, it could either go through one of the protein channels, or be taken in by means of endocytosis.

More general information on this topic may be found in the article at cell membrane.

See also


'"/>


(Date:9/18/2014)... matter how many times it,s demonstrated, it,s still ... , But by using a signaling system ... their behavior to suit their population. In short, ... present, and act accordingly. , Once the population ... change from innocuous to pathogenic, or from unhelpful ...
(Date:9/18/2014)... information is stored in DNA, tiny strands of nucleic ... bodies. To express this genetic data, our DNA is ... into proteins that perform tasks in our cells. ... of RNA molecule. Unlike all other known RNAs, this ... circRNA molecules are abundant, little has been known about ...
(Date:9/18/2014)... 2014Many Americans across racial and ethnic groups describe ... on their day-to-day life, more so than other ... speech (57% of African-Americans, 49% of non-Hispanic whites, ... asked which disease or ailment is the worst ... among African-Americans followed by AIDS/HIV. Hispanics and ...
Breaking Biology News(10 mins):Researchers study vital 'on/off switches' that control when bacteria turn deadly 2Researchers study vital 'on/off switches' that control when bacteria turn deadly 3Scientists find how mysterious 'circular RNA' is formed, claim muscular dystrophy link 2Americans rate losing eyesight as having greatest impact on their lives 2Americans rate losing eyesight as having greatest impact on their lives 3
... heart-healthy, essential omega-3 fatty acid is about to improve ... advance will move biotechnology onto the average consumer,s daily ... deliver positive environmental impacts and increase production to feed ... on Horizon , Recently, the U.S. Food and Drug ...
... COLLEGE STATION "Four and 20 black birds baked in ... discovery, backed by DNA analysis, means scientists now know there is ... Africa than was previously thought. And if Dr. Gary Voelker has ... its susceptibility to the deforestation now occurring across its native habitat. ...
... two different protection programs to safeguard them from getting ... stopping and developing cancer. Until now, researchers assumed that ... Now for the first time, using an animal model ... (MDC) Berlin-Buch and the Charit University Hospital Berlin ...
Cached Biology News:New biotech advance to add heart healthy omega-3s to US diet 2African bird discovery proves there is something new under the sun 22 at 1 stroke -- how cells protect themselves from cancer 2
Other biology definitionOther Tags