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Membrane
 
 
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A membrane is a layer of material which serves as a selective barrier between two phases
Phase (matter)

In the physical sciences, a phase is a region of space , throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, refractive index, and chemical composition....
 and remains impermeable
Permeation

Permeation, in physics and engineering, is the penetration of a permeate through a solid, and is related to a material's intrinsic permeability....
 to specific particles or group of particles or substances when exposed to the action of a driving force
Membrane potential

Membrane potential , is the voltage difference between the interior and exterior of a cell. Because the fluid inside and outside a cell is highly conductive, whereas a cell's plasma membrane is highly resistive, the voltage change in moving from a point outside to a point inside occurs largely within the narrow width of the membrane itself...
. Some components are allowed passage by the membrane into a permeate stream, whereas others are retained by it and accumulate in the retentate stream
Stream

A stream is a body of water less than 60 feet wide with a current , confined within a stream bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as brook, beck, Burn , creek, crick, kill, lick , rill, river syke, bayou, rivu...
.

Membranes can be of various thickness, with homogeneous or heterogeneous
Heterogeneous

Heterogeneous is an adjective used to describe an object or system consisting of multiple items having a large number of structural variations. It is the opposite of homogeneous, which means that an object or system consists of multiple identical items....
 structure.






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A membrane is a layer of material which serves as a selective barrier between two phases
Phase (matter)

In the physical sciences, a phase is a region of space , throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, refractive index, and chemical composition....
 and remains impermeable
Permeation

Permeation, in physics and engineering, is the penetration of a permeate through a solid, and is related to a material's intrinsic permeability....
 to specific particles or group of particles or substances when exposed to the action of a driving force
Membrane potential

Membrane potential , is the voltage difference between the interior and exterior of a cell. Because the fluid inside and outside a cell is highly conductive, whereas a cell's plasma membrane is highly resistive, the voltage change in moving from a point outside to a point inside occurs largely within the narrow width of the membrane itself...
. Some components are allowed passage by the membrane into a permeate stream, whereas others are retained by it and accumulate in the retentate stream
Stream

A stream is a body of water less than 60 feet wide with a current , confined within a stream bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as brook, beck, Burn , creek, crick, kill, lick , rill, river syke, bayou, rivu...
.

Membranes can be of various thickness, with homogeneous or heterogeneous
Heterogeneous

Heterogeneous is an adjective used to describe an object or system consisting of multiple items having a large number of structural variations. It is the opposite of homogeneous, which means that an object or system consists of multiple identical items....
 structure. Membrane can be neutral or charged, and particles transport can be active
Active transport

Active transport is the mediated process of moving particles across a biological membrane against a Concentration_gradient#In_biology . If the process uses chemical energy, such as from adenosine triphosphate , it is termed primary active transport....
 or passive
Passive transport

Passive transport means Motion biochemistrys and atomic or molecular substances across the The four main kinds of passive transport are diffusion, facilitated diffusion, filtration and osmosis....
. The latter can be facilitated by pressure, concentration, chemical or electrical gradients of the membrane process. Membranes can be generally classified into two groups: artificial membrane
Artificial membrane

Artificial membrane also known as synthetic membrane is a syntheticly created membrane which is usually intended for separation purposes in laboratory or in industry....
s or biological membrane
Biological membrane

A biological membrane or biomembrane is an enclosing or separating amphipathic layer that acts as a barrier within or around a cell . It is, almost invariably, a lipid bilayer, composed of a double layer of lipid-class molecules, specifically phospholipids and cholesterol, with occasional integral membrane protein intertwined, some o...
s. These two types of membranes differ significantly in their structure and functionality.

Biological


Artificial


Membranes in Popular Culture


Membranes were mentioned in the Cypress Hill song "Insane in the Brain." The chorus features B-real repeating the title of the song but, in a nonsensical though thematically appropriate fashion, replacing the word "brain" with "membrane."

See also

  • Basement membrane
    Basement membrane

    The basement membrane is a sheet of cells and fibers that covers two other kinds of cells -- the epithelium, which lines the cavities and surfaces of organs, and the endothelium, which lines the interior surface of blood vessels....
  • Cell membrane
    Cell membrane

    The cell membrane is the interface between the cellular machinery inside the cell and the fluid outside.It is a semipermeable lipid bilayer found in all cell ....
  • Inner membrane
    Inner membrane

    The inner membrane is the biological membrane of an organelle or Gram-negative bacteria that is within an outer membrane.In eukaryotic cells, this inner membrane is present within the nuclear envelope, mitochondria and plastids like the chloroplast....
  • Membrane (M-Theory)
  • Mucous membrane
    Mucous membrane

    The mucous membranes are linings of mostly germ layer origin, covered in epithelium, which are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organ ....
  • Outer membrane
    Outer membrane

    The bacterial outer membrane is found in Gram-negative bacteria. Its composition is distinct from that of the cytoplasmic membrane - among other things, the outer leaflet of the membrane include a complex lipopolysaccharide whose lipid portion acts as an endotoxin - and it is linked to the cell's peptidoglycan by Braun's lipoprotein....
  • Serous membrane
    Serous membrane

    In anatomy, a serous membrane is a smooth Mesothelium consisting of a thin layer of Cell which excrete serous fluid. Serous membranes line and enclose several body cavities, known as serous cavities, where they secrete a lubricating fluid which reduces friction from muscle movement....
  • Vibrations of a circular drum
    Vibrations of a circular drum

    The vibrations of an idealized circular drum, essentially an elastic membrane of uniform thickness attached to a rigid circular frame, are solutions of the wave equation with Dirichlet boundary conditions....