Membrane
hideA membrane is a layer of material which serves as a selective barrier between two phases and remains impermeable to specific particles, molecules, or substances when exposed to the action of a driving force. Some components are allowed passage by the membrane into a permeate stream, whereas others are retained by it and accumulate in the retentate stream.
Membranes can be of various thickness, with homogeneous or heterogeneous structure. Membrane can also be classified according to their pore diameter. According to IUPAC, there are three different types of pore size classifications: microporous (dp < 2nm), mesoporous (2nm < dp < 50nm) and macroporous (dp > 50nm). Membranes can be neutral or charged, and particles transport can be active or passive. The latter can be facilitated by pressure, concentration, chemical or electrical gradients of the membrane process. Membranes can be generally classified into three groups: inorganic, polymeric or biological membranes. These three types of membranes differ significantly in their structure and functionality.
For more information about Membrane, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with membrane
Chemical energy influences tiny vibrations of red blood cell membranes
Dec 21, 2009 |
4.8 / 5 (6) |
0
(PhysOrg.com) -- Much like a tightly wound drum, red blood cells are in perpetual vibration. Those vibrations help the cells maintain their characteristic flattened oval or disc shape, which is critical to ...
Researchers create new 'smart' nanocapsule delivery system for use in protein therapy
Nanotechnology / Bio & Medicine
Dec 18, 2009 |
5 / 5 (3) |
1
the delivery of healthy proteins directly into human cells to replace malfunctioning proteins — is considered one of the most direct and safe approaches for treating diseases. But its effectiveness has been limited by low ...
Synthetic protein mimics structure, function of metalloprotein in nature
Dec 10, 2009 |
5 / 5 (1) |
1
Scientists have designed a synthetic protein that is both a structural model and a functional model of a native protein, nitric-oxide reductase.
A cell's 'cap' of bundled fibers could yield clues to disease (w/ Video)
Dec 02, 2009 |
4 / 5 (1) |
0
It turns out that wearing a cap is good for you, at least if you are a mammal cell.
Nervy research: Researchers take initial look at ion channels in a model system
Dec 02, 2009 |
5 / 5 (1) |
0
Before one of your muscles can twitch, before the thought telling it to flex can race down your nerve, a tiny floodgate of sorts -- called an ion channel -- must open in the surface of each cell in these organs ...
