Related topics: cells · cell membrane

Researchers discover crystalline zeolites in a nanotubular shape

Zeolites, which are crystalline porous materials, are very widely used in the production of chemicals, fuels, materials, and other products.  So far, zeolites have been made as 3D or 2D materials. This has changed with the ...

Why do mitochondria look like they do?

One of the biggest challenges in biology today is to explain the structure of cristae, the inner membranes of mitochondria. An explanation in this case is a set of principles to predict what form the cristae will take after ...

The novel flight style that helps the smallest beetles to excel

An international team of researchers describes in detail the mechanisms of the extraordinarily fast flight of the smallest free-living insects, beetles of the featherwing family (Ptiliidae). The team includes members and ...

How pathogens can turn off mitochondrial defense mechanisms

Mitochondria are known as energy suppliers for our cells, but they also play an important role in the defense against pathogens. They can initiate immune responses, and deprive pathogens of the nutrients they need to grow. ...

page 1 from 40


A 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.

This text uses material from Wikipedia, licensed under CC BY-SA