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Information about Biological Membrane

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A biological membrane or biomembrane is an enclosing or separating tissue which 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, with occasional proteins intertwined, some of which function as channels.

Function

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, and are called membrane-bound organelles.

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. Biological membranes also have certain mechanical or elastic properties.

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.

Types of biological membranes

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Biological tissue is a collection of interconnected cells that perform a similar function within an organism.

The study of tissue is known as histology, or, in connection with disease, histopathology.
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lipid bilayer or bilayer lipid membrane (BLM) is a membrane or zone of a membrane composed of lipid molecules (usually phospholipids). The lipid bilayer is a critical component of all biological membranes, including cell membranes, and so is absolutely essential for all
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Lipids can be broadly defined as any fat-soluble (hydrophobic), naturally-occurring molecules. The term is more-specifically used to refer to fatty-acids and their derivatives (including tri-, di-, and monoglycerides and phospholipids) as well as other fat-soluble sterol-containing
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molecule is defined as a sufficiently stable electrically neutral group of at least two atoms in a definite arrangement held together by strong chemical bonds.[1][2] In organic chemistry and biochemistry, the term molecule
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U indicates the uncharged hydrophobic portion of the molecule, highlighted in blue.]]

Phospholipids are a class of lipids, and a major component of all biological membranes, along with glycolipids, cholesterol and proteins.
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An Integral Membrane Protein (IMP) is a protein molecule (or assembly of proteins) that is permanently attached to the biological membrane. Such proteins can be separated from the biological membranes only using detergents, nonpolar solvents, or sometimes denaturing agents.
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Ion channels are pore-forming proteins that help to establish and control the small voltage gradient across the plasma membrane of all living cells (see cell potential) by allowing the flow of ions down their electrochemical gradient.
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Coat of arms elements


In heraldry, a compartment is a design placed under the shield, usually rocks, a grassy mount, or some sort of other landscape upon which the supporters are depicted as standing.
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Biochemistry is the study of the chemical processes in living organisms.[1] The word "biochemistry" comes from the Greek word βιοχημεία biochēmeia, which means "the chemistry of life.
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natural environment, commonly referred to simply as the environment, is a term that comprises all living and non-living things that occur naturally on Earth or some part of it (e.g. the natural environment in a country).
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Peroxisomes are ubiquitous organelles in eukaryotes that participate in the metabolism of fatty acids and other metabolites. Peroxisomes have enzymes that rid the cell of toxic peroxides.
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A peroxide is a compound containing an oxygen-oxygen single bond. The simplest stable peroxide is hydrogen peroxide. Superoxides, dioxygenyls, ozones and ozonides compound are considered separately.
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In cell biology, an organelle is a specialized subunit within a cell, having a specific function, and separately enclosed within its own lipid membrane.

The name organelle
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semipermeable membrane, also termed a selectively permeable membrane, a partially permeable membrane or a differentially permeable membrane, is a membrane which will allow certain molecules or ions to pass through it by diffusion and occasionally specialized
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Flavour in particle physics
 

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The phrase "chemical property" is context-dependent, but generally refers to a material's behavior at ambient conditions (i.e. room temperature, atmospheric pressure, oxygen-bearing atmosphere).
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atom (Greek ἄτομος or átomos meaning "indivisible") is the smallest particle still characterizing a chemical element.
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175 (1972) 720]. In this model, the cell membrane is considered as a lipid bilayer where the lipid molecules can move freely in the membrane surface like fluid, while the proteins are embedded in the lipid bilayer.
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Endocytosis (IPA: /ˌɛndoʊsaɪˈtoʊsɨs/) is a process whereby cells absorb material (molecules such as proteins) from the outside by engulfing it with their cell membrane.
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The mucous membranes (or mucosae; singular: mucosa) are linings of mostly endodermal origin, covered in epithelium, and are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs.
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An S-layer (surface layer) is a part of the cell envelope commonly found in bacteria, as well as among archaea. It consists of a monomolecular layer composed of identical proteins or glycoproteins.
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The three major classes of membrane lipids are phospholipids, glycolipids, and cholesterol.

Phospholipids

Phospholipids and glycolipids consist of two long, nonpolar (hydrophobic) hydrocarbon chains linked to a hydrophilic head group.
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endomembrane system is the system of internal membranes within eukaryotic cells that divide the cell into functional and structural compartments, or organelles. Prokaryotes do not have an endomembrane system and thus lack most organelles.
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The outer membrane refers to the outside membranes of Gram-negative bacteria, the chloroplast, or the mitochondria. It is used to maintain the shape of the organelle contained within its structure, and it acts as a barrier against certain dangers.
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inner membrane is the cell membrane (phospholipid bilayer) 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.
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biofilm is a complex aggregation of microorganisms marked by the excretion of a protective and adhesive matrix. Biofilms are also often characterized by surface attachment, structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of
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