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The inner membrane is the 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...
 (phospholipid bilayer) of an organelle
Organelle

In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid membrane....
 or Gram-negative
Gram-negative

Gram-negative bacteria are those bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color....
 bacteria
Bacteria

The Bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals....
 that is within an 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....
.

In eukaryotic cells, this inner membrane is present within the nuclear envelope
Nuclear envelope

The nuclear envelope is a double lipid bilayer that encloses the genetic material in eukaryote cell . The nuclear envelope also serves as the physical barrier, separating the contents of the nucleus from the cytosol ....
, mitochondria and plastid
Plastid

Plastids are major organelles found in plants and algae. Plastids are the site of manufacture and storage of important chemical compounds used by the cell....
s like the chloroplast
Chloroplast

Chloroplasts are organelles found in plant cells and other eukaryote organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve Thermodynamic free energy in the form of Adenosine triphosphate and reduce NADP to NADPH through a complex set of processes called photosynthesis....
.






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Diagram Human Cell Nucleus
Mitochondrie
Chloroplast New
The inner membrane is the 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...
 (phospholipid bilayer) of an organelle
Organelle

In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid membrane....
 or Gram-negative
Gram-negative

Gram-negative bacteria are those bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color....
 bacteria
Bacteria

The Bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals....
 that is within an 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....
.

In eukaryotic cells, this inner membrane is present within the nuclear envelope
Nuclear envelope

The nuclear envelope is a double lipid bilayer that encloses the genetic material in eukaryote cell . The nuclear envelope also serves as the physical barrier, separating the contents of the nucleus from the cytosol ....
, mitochondria and plastid
Plastid

Plastids are major organelles found in plants and algae. Plastids are the site of manufacture and storage of important chemical compounds used by the cell....
s like the chloroplast
Chloroplast

Chloroplasts are organelles found in plant cells and other eukaryote organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve Thermodynamic free energy in the form of Adenosine triphosphate and reduce NADP to NADPH through a complex set of processes called photosynthesis....
. The lumen between the inner and outer membranes is referred to as intermembrane space
Intermembrane space

The intermembrane space is the region between the inner membrane and the outer membrane of a mitochondrion or a chloroplast. The main function of the intermembrane space is oxidative phosphorylation....
.

In prokaryotic
Prokaryote

The prokaryotes are a group of organisms that lack a cell nucleus , or any other cell membrane-bound organelles. They differ from the eukaryotes, which have a cell nucleus....
 cells such as many Gram-negative bacteria, the space between the inner and outer membrane is commonly referred to as the periplasmic space
Periplasmic space

The periplasmic space or periplasm is a space between the inner cytoplasmic membrane and external outer membrane of Gram-negative bacterium or the equivalent space between the cell membrane and cell wall in Gram-positive bacteria....
 or periplasm. The inner membrane may also be referred to as the cytoplasmic 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 ....
 and it is similar in structure and protein content as the cytoplasmic membrane of other bacteria that contain only one membrane (such as most Gram-positive
Gram-positive

Gram-positive Bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink....
 bacteria).

This structural arrangement of an inner and outer membrane is thought to be similar in Gram-negative bacteria, mitochondria and chloroplasts due to their ancestral relationship, as outlined in the endosymbiotic theory
Endosymbiotic theory

The endosymbiotic theory concerns the origins of mitochondrion and plastids , which are organelles of eukaryote cells. According to this theory, these organelles originated as separate prokaryote organisms which were taken inside the cell as endosymbionts....
.

Inner membrane of the nuclear envelope

The inner membrane of the nuclear envelope
Nuclear envelope

The nuclear envelope is a double lipid bilayer that encloses the genetic material in eukaryote cell . The nuclear envelope also serves as the physical barrier, separating the contents of the nucleus from the cytosol ....
 is connected to the outer nuclear envelope membrane through nuclear pore
Nuclear pore

Nuclear pores are large protein complexes that cross the nuclear envelope, which is the double Endomembrane system surrounding the eukaryote cell cell nucleus....
s. It contains a number of proteins involved in the structural organization of the nucleus and the attachment of chromatin
Chromatin

Chromatin is the complex combination of DNA, RNA, and protein that makes up chromosomes. It is found inside the cell nucleus of Eukaryote cell , and within the nucleoid in prokaryotic cells....
 to the nuclear envelope. In metazoan cells, the inner nuclear membrane contains proteins of the nuclear lamina
Nuclear lamina

The nuclear lamina is a dense fibrillar network inside the Cell nucleus of an eukaryotic cell. It is composed of intermediate filaments and membrane associated proteins....
, a protein meshwork underlying the nuclear envelope and providing structural support. Mutations in inner nuclear envelope proteins can cause nuclear envelopathies, a number of genetic disorder
Genetic disorder

A genetic disorder is an illness caused by abnormalities in genes or chromosomes. While some diseases, such as cancer, are due in part to a genetic disorders, they can also be caused by Environment factors....
s in humans.

Mitochondrial inner membrane

See main article at Inner mitochondrial membrane
Inner mitochondrial membrane

The mitochondrial inner membrane forms internal compartments known as cristae, which allow greater space for the proteins such as cytochromes to function properly and efficiently....
The mitochondrial inner membrane forms internal compartments known as crista
Crista

Cristae are the internal compartments formed by the Inner mitochondrial membrane of a mitochondrion. They are studded with proteins, including ATP synthase and a variety of cytochromes....
e, which allow greater space for the proteins such as cytochrome
Cytochrome

Cytochromes are, in general, membrane-bound hemoproteins that contain heme groups and carry out electron transport.They are found either as subunitss or as subunits of bigger enzymatic complexes that catalyze redox reactions....
s to function properly and efficiently.

Plastidial inner membrane

The plastid
Plastid

Plastids are major organelles found in plants and algae. Plastids are the site of manufacture and storage of important chemical compounds used by the cell....
ial inner membrane surrounds the stroma of the plastid. In chloroplast
Chloroplast

Chloroplasts are organelles found in plant cells and other eukaryote organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve Thermodynamic free energy in the form of Adenosine triphosphate and reduce NADP to NADPH through a complex set of processes called photosynthesis....
s, extensions of the inner membrane form the thylakoid
Thylakoid

A thylakoid is a membrane-bound compartment inside chloroplasts and cyanobacterium. They are the site of the light-dependent reactions of photosynthesis....
 membrane where the photosystem
Photosystem

Photosystems are protein complexes involved in photosynthesis. They are found in the thylakoid membranes of plants, algae and cyanobacteria , or in the cytoplasmic membrane of photosynthetic bacteria....
s for photosynthesis
Photosynthesis

File:Seawifs global biosphere.jpgPhotosynthesis is a metabolic pathway that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight....
 are located. The inner and thylakoid membranes are very similar to the membranes found in cyanobacteria. Similar to mitochondria, plastids are thought to have evolved from bacterial endosymbiont
Endosymbiont

An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis . Examples are nitrogen-fixing bacterium which live in root nodules on legume roots, single-celled algae inside reef-building corals, and bacterial endosymbionts that provide essential nutrients to about 10%?15% of in...
s.

See also


For eukaryotes
  • Intermembrane space
    Intermembrane space

    The intermembrane space is the region between the inner membrane and the outer membrane of a mitochondrion or a chloroplast. The main function of the intermembrane space is oxidative phosphorylation....
  • Chloroplast membrane
    Chloroplast membrane

    Chloroplasts contain several important biological membranes, vital for their function. Like mitochondria, chloroplasts have a double-membrane envelope, called the chloroplast envelope....


For bacteria
  • periplasmic space
    Periplasmic space

    The periplasmic space or periplasm is a space between the inner cytoplasmic membrane and external outer membrane of Gram-negative bacterium or the equivalent space between the cell membrane and cell wall in Gram-positive bacteria....
  • 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....