Arachidonic acid (AA) is an omega-6 fatty acid 20:4(ω-6). It is the counterpart to the saturated arachidic acid found in peanut oil, (L. arachis – peanut.)^[1] Image File history File links Download high-resolution version (1353x147, 4 KB) Chemical structure of arachidonic acid created with ChemDraw. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article or section does not cite any references or sources. ... The molecular mass (abbreviated Mr) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... Italic text This article is about the boiling point of liquids. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Omega-6 fatty acids are fatty acids where the term omega-6 signifies that the first double bond in the carbon backbone of the fatty acid, counting from the end opposite the acid group, occurs in the sixth carbon-carbon bond. ... Arachidic acid also called eicosanoic acid is a saturated fatty acid found in peanut oil. ... Binomial name L. This article is about the legume. ...

Chemical characteristics

Chemically, arachidonic acid is ancarboxylic acid with a 20-carbon chain and four cis double bonds; the first double bond is located at the sixth carbon from the omega end. Structure of a carboxylic acid The 3D structure of the carboxyl group A space-filling model of the carboxyl group Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the formula -C(=O)OH, usually written -COOH or -CO2H. [1] Carboxylic acids are Bronsted... CIS usually refers to: Commonwealth of Independent States, a modern-day political entity consisting of 11 former Soviet Union Republics CIS is also an acronym for: Canadian Interuniversity Sport Cancer Information Service Carcinoma in situ Centre for Independent Studies Center for Immigration Studies Chinese International School Cisalpino Citizenship & Immigration Services...

Some chemistry sources define 'arachidonic acid' to designate any of the eicosatetraenoic acids. However, almost all writings in biology, medicine and nutrition limit the term to all-cis 5,8,11,14-eicosatetraenoic acid. Eicosatetraenoic acid designates any straight chain 20:4 fatty acid. ...

Biological role

Arachidonic acid is a polyunsaturated fatty acid that is present in the phospholipids (especially phosphatidylethanolamine, phosphatidylcholine and phosphatidylinositides) of membranes of the body's cells, and is abundant in the brain. Phospholipid Two schematic representations of a phospholipid. ... Phosphatidylethanolamine is a lipid found in biological membranes. ... Lecithin, also known as Phosphatidylcholine Lecithin is usually used as synonym for phosphatidylcholine, a phospholipid which is the major component of a phosphatide fraction which may be isolated from either egg yolk (in Greek lekithos - λεκιθος), or soy beans. ... Chemical structure of sn-1-stearoyl-2-arachidonoyl phosphatidylinositol Phosphatidylinositol (abbreviated PtdIns, or PI) is a minor phospholipid component in the cytosolic side of eukaryotic cell membranes. ... The cell membrane (also called the plasma membrane, plasmalemma or phospholipid bilayer) is a semipermeable lipid bilayer common to all living cells. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... In animals, the brain or encephalon (Greek for in the head), is the control center of the central nervous system, responsible for behaviour. ...

It is also involved in cellular signaling as a second messenger. Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions. ... In biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay signals within a cell. ...

It is the source of several other molecules with specific roles, as described in the next section.

Synthesis and cascade

Eicosanoid synthesis.

Arachidonic acid is freed from phospholipid molecule by the enzyme phospholipase A2, which cleaves off the fatty acid precursor (usually linoleic acid). Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Phospholipid Two schematic representations of a phospholipid. ... A phospholipase is an enzyme that converts phospholipids into fatty acids and other lipophilic substances. ... In chemistry, especially biochemistry, a fatty acid is a carboxylic acid often with a long unbranched aliphatic tail (chain), which is either saturated or unsaturated. ... The chemical strucuture of linoleic acid showing physiological numbering (red) and chemical numbering (blue) conventions. ...

Arachidonic acid is a precursor in the production of eicosanoids: In biochemistry, eicosanoids are a class of oxygenated hydrophobic molecules that largely function as autocrine and paracrine mediators. ...

• the enzymes cyclooxygenase and peroxidase lead to Prostaglandin H2, which in turn is used to produce the prostaglandins, prostacyclin, and thromboxanes.
• the enzyme 5-lipoxygenase leads to 5-HPETE, which in turn is used to produce the leukotrienes.
• arachidonic acid is also used in the biosynthesis of anandamide.

The production of these derivatives, and their action in the body, are collectively known as the arachidonic acid cascade; see essential fatty acid interactions for more details. Cyclooxygenase (COX) is an enzyme (EC 1. ... Glutathione Peroxidase 1 A peroxidase (eg. ... Prostaglandin H2 is a type of Prostaglandin which is derived from arachidonic acid and is a precursor for many other biologically signficant molecules: Eicosanoid synthesis. ... Chemical structure of prostaglandin E1 (PGE1). ... Prostacyclin is a member of the family of lipid molecules known as eicosanoids. ... Thromboxane is a member of the family of lipids known as eicosanoids. ... Lipoxygenases are iron-containing enzymes that catalyse the dioxygenation of polyunsaturated fatty acids in reaction: fatty acid + O2 = fatty acid hydroperoxide Lipoxygenases are found in plants and in animals. ... Arachidonic acid 5-hydroperoxide (5-hydroperoxyeicosatetraenoic acid, 5-HPETE) is an intermediate in the production of leukotriene A4 from arachidonic acid. ... Leukotrienes are autocrine and paracrine eicosanoid lipid mediators derived from arachidonic acid by 5-lipoxygenase. ... Anandamide, also known as arachidonoylethanolamine or AEA, is a naturally occurring endogenous cannabinoid neurotransmitter found in the brain of animals, as well as other organs. ... The actions of the ω-3 and ω-6 essential fatty acids (EFAs) are best characterized by their interactions; they cannot be understood separately. ...

Arachidonic acid as an essential fatty acid

Arachidonic acid in the human body comes from dietary animal sources—meat, eggs, dairy—or is synthesized from linoleic acid.

Arachidonic acid is one of the essential fatty acids required by most mammals. Some mammals lack the ability to—or have a very limited capacity to—convert linoleic acid into arachidonic acid, making it an essential part of their diet. Since little or no arachidonic acid is found in plants, such animals are obligate carnivores; the cat is a common example.^[2][3]

Arachidonic acid is a non-essential fatty acid in humans. The two essential fatty acids in humans are:
1) Linoleic Acid
2) Linolenic Acid Image File history File links Steaks. ... Image File history File links Steaks. ... Essential fatty acids, or EFAs, are fatty acids that cannot be constructed within an organism from other components (generally all references are to humans) by any known chemical pathways; and therefore must be obtained from the diet. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in... The chemical strucuture of linoleic acid showing physiological numbering (red) and chemical numbering (blue) conventions. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta—liverworts Anthocerotophyta—hornworts Bryophyta—mosses Vascular plants (tracheophytes) †Rhyniophyta—rhyniophytes †Zosterophyllophyta—zosterophylls Lycopodiophyta—clubmosses †Trimerophytophyta—trimerophytes Pteridophyta—ferns and horsetails Seed plants (spermatophytes) †Pteridospermatophyta—seed ferns Pinophyta—conifers Cycadophyta—cycads Ginkgophyta—ginkgo Gnetophyta—gnetae Magnoliophyta—flowering plants... This tigers sharp teeth and strong jaws are the classical physical traits expected from carnivorous mammalian predators A carnivore (IPA: ), meaning meat eater (Latin carne meaning flesh and vorare meaning to devour), is an animal that eats a diet consisting mainly of meat, whether it comes from live animals... Binomial name Felis catus Linnaeus, 1758 Synonyms Felis lybica invalid junior synonym The cat (or domestic cat, house cat) is a small carnivorous mammal. ...

References

1. ^ Dorland's Medical Dictionary – 'A'. Retrieved on 2007-01-12.
2. ^ MacDonald M, Rogers Q, Morris J (1984). "Nutrition of the domestic cat, a mammalian carnivore". Annu Rev Nutr 4: 521-62. PMID 6380542. Retrieved on 2007-02-09. 
3. ^ Rivers J, Sinclair A, Crawford M (1975). "Inability of the cat to desaturate essential fatty acids". Nature 258 (5531): 171-3. DOI:10.1038/258171a0. PMID 1186900. 

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 12th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 40th day of the year in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

See also

• Polyunsaturated fat
• Polyunsaturated fatty acid
• Aspirin - inhibits cyclooxygenase enzyme to prevent the conversion of arachidonic acid to other signal molecules

// In nutrition, polyunsaturated fat is an abbreviation of polyunsaturated fatty acid. ... A polyunsaturated fatty acid (PUFA) is a class of unsaturated fat that contains more than one double bond. ... Aspirin, or acetylsalicylic acid (IPA: ), (acetosal) is a drug in the family of salicylates, often used as an analgesic (to relieve minor aches and pains), antipyretic (to reduce fever), and as an anti-inflammatory. ...

External links

• Arachidonic Acid at acnp.org
• MeSH Arachidonic+Acid