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Desaturase
A fatty acid desaturase is an enzyme that removes two hydrogen atoms from a fatty acid, creating a carbon/carbon double bond. These desaturases are classified as: * Delta - indicating that the double bond is created at a fixed position from the carboxyl end of a fatty acid chain. For example, Δ9 desaturase creates a double bond between the ninth and tenth carbon atom from the carboxyl end. * Omega - indicating the double bond is created at a fixed position from the methyl end of a fatty acid chain. For instance, ω3 desaturase creates a double bond between the third and fourth carbon atom from the methyl end. In other words, it creates an omega-3 fatty acid. For example, Δ6 desaturation introduces a double bond between carbons 6 and 7 of Linoleic acid (LA C18H32O2; 18:2-n6) and α-Linolenic acid (ALA: C18H30O2; 18:3-n3), creating ''γ''-linolenic acid (GLA: C18H30O2,18:3-n6) and stearidonic acid (SDA: C18H28O2; 18:4-n3) respectively. In humans, Δ17- desaturase is able to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stearoyl-CoA Desaturase-1
Stearoyl-CoA desaturase (Δ-9-desaturase) is an endoplasmic reticulum enzyme that catalyzes the rate-limiting step in the formation of monounsaturated fatty acids (MUFAs), specifically oleate and palmitoleate from stearoyl-CoA and palmitoyl-CoA. Oleate and palmitoleate are major components of membrane phospholipids, cholesterol esters and alkyl-diacylglycerol. In humans, the enzyme is encoded by the SCD gene. Stearoyl-CoA desaturase-1 is a key enzyme in fatty acid metabolism. It is responsible for forming a double bond in Stearoyl-CoA. This is how the monounsaturated fatty acid oleic acid is produced from the saturated fatty acid stearic acid. A series of redox reactions, during which two electrons flow from NADH to flavoprotein cytochrome b5, then to the electron acceptor cytochrome b5 as well as molecular oxygen introduces a single double bond within a row of methylene fatty acyl-CoA substrates. The complexed enzyme adds a single double bond between the C9 and C10 of l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stearoyl-CoA Desaturase-1
Stearoyl-CoA desaturase (Δ-9-desaturase) is an endoplasmic reticulum enzyme that catalyzes the rate-limiting step in the formation of monounsaturated fatty acids (MUFAs), specifically oleate and palmitoleate from stearoyl-CoA and palmitoyl-CoA. Oleate and palmitoleate are major components of membrane phospholipids, cholesterol esters and alkyl-diacylglycerol. In humans, the enzyme is encoded by the SCD gene. Stearoyl-CoA desaturase-1 is a key enzyme in fatty acid metabolism. It is responsible for forming a double bond in Stearoyl-CoA. This is how the monounsaturated fatty acid oleic acid is produced from the saturated fatty acid stearic acid. A series of redox reactions, during which two electrons flow from NADH to flavoprotein cytochrome b5, then to the electron acceptor cytochrome b5 as well as molecular oxygen introduces a single double bond within a row of methylene fatty acyl-CoA substrates. The complexed enzyme adds a single double bond between the C9 and C10 of l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid Synthesis
In biochemistry, fatty acid synthesis is the creation of fatty acids from acetyl-CoA and NADPH through the action of enzymes called fatty acid synthases. This process takes place in the cytoplasm of the cell. Most of the acetyl-CoA which is converted into fatty acids is derived from carbohydrates via the glycolytic pathway. The glycolytic pathway also provides the glycerol with which three fatty acids can combine (by means of ester bonds) to form triglycerides (also known as "triacylglycerols" – to distinguish them from fatty "acids" – or simply as "fat"), the final product of the lipogenic process. When only two fatty acids combine with glycerol and the third alcohol group is phosphorylated with a group such as phosphatidylcholine, a phospholipid is formed. Phospholipids form the bulk of the lipid bilayers that make up cell membranes and surrounds the organelles within the cells (such as the cell nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-Linolenic Acid
''alpha''-Linolenic acid (ALA), also known as α-Linolenic acid (from Greek ''alpha'' meaning "first" and ''linon'' meaning flax), is an ''n''−3, or omega-3, essential fatty acid. ALA is found in many seeds and oils, including flaxseed, walnuts, chia, hemp, and many common vegetable oils. In terms of its structure, it is named ''all''-''cis''-9,12,15-octadecatrienoic acid. In physiological literature, it is listed by its lipid number, 18:3, and (''n''−3). It is a carboxylic acid with an 18-carbon chain and three '' cis'' double bonds. The first double bond is located at the third carbon from the methyl end of the fatty acid chain, known as the ''n'' end. Thus, α-linolenic acid is a polyunsaturated ''n''−3 (omega-3) fatty acid. It is an isomer of gamma-linolenic acid (GLA), an 18:3 (''n''−6) fatty acid (i.e., a polyunsaturated omega-6 fatty acid with three double bonds). Etymology The word ''linolenic'' is an irregular derivation from ''linoleic'', which itse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FADS1
Fatty acid desaturase 1 is an enzyme that in humans is encoded by the ''FADS1'' gene. Function The protein encoded by the FADS1 gene is a member of the fatty acid desaturase (FADS) gene family and desaturates omega-3 and omega-6 polyunsaturated fatty acids at the delta-5 position, catalyzing the final step in the formation of eicosapentaenoic acid (EPA) and Arachidonic acid. Desaturase enzymes (such as those encoded by FADS1) regulate unsaturation of fatty acids through the introduction of double bonds between defined carbons of the fatty acyl chain. FADS family members are considered fusion products composed of an N-terminal cytochrome b5-like domain and a C-terminal multiple membrane-spanning desaturase portion, both of which are characterized by conserved histidine motifs. This gene is clustered with family members FADS1 and FADS2 at 11q12-q13.1; this cluster is thought to have arisen evolutionarily from gene duplication based on its similar exon/intron organization. Clin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta 6 Desaturase
In enzymology, a linoleoyl-CoA desaturase (also Delta 6 desaturase, ) is an enzyme that converts between types of fatty acids, which are essential nutrients in the human body. The enzyme mainly catalyzes the chemical reaction :linoleoyl-CoA + AH2 + O2 \rightleftharpoons gamma-linolenoyl-CoA + A + 2 H2O The 3 substrates of this enzyme are linoleoyl-CoA, an electron acceptor AH2, and O2, whereas its 3 products are gamma-linolenoyl-CoA, the reduction product A, and H2O. This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with oxidation of a pair of donors resulting in the reduction of O to two molecules of water. The systematic name of this enzyme class is linoleoyl-CoA,hydrogen-donor:oxygen oxidoreductase. Other names in common use include Delta6-desaturase (D6D or Δ-6-desaturase), Delta6-fatty acyl-CoA desaturase, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Fatty Acid
Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them. Only two fatty acids are known to be essential for humans: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid). These are supplied to the body both as the free fatty acid or more commonly as some glyceride derivative. Deficiency in these fatty acids is rare. These fatty acids are essential because they are precursors to vitamins, cofactors. These derivatives include prostaglandins, leukotrienes, thromboxanes, lipoxins, and others. When the two EFAs were discovered in 1923, they were designated "vitamin F", but in 1929, research on rats showed that the two EFAs are better classified as fats rather than vitamins. Functions :''The biological effects of the ω-3 and ω-6 fatty acids are mediated by their mutual interactions, see Essential fatty acid interactions for detail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta-6-desaturase
In enzymology, a linoleoyl-CoA desaturase (also Delta 6 desaturase, ) is an enzyme that converts between types of fatty acids, which are essential nutrients in the human body. The enzyme mainly catalyzes the chemical reaction :linoleoyl-CoA + AH2 + O2 \rightleftharpoons gamma-linolenoyl-CoA + A + 2 H2O The 3 substrates of this enzyme are linoleoyl-CoA, an electron acceptor AH2, and O2, whereas its 3 products are gamma-linolenoyl-CoA, the reduction product A, and H2O. This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with oxidation of a pair of donors resulting in the reduction of O to two molecules of water. The systematic name of this enzyme class is linoleoyl-CoA,hydrogen-donor:oxygen oxidoreductase. Other names in common use include Delta6-desaturase (D6D or Δ-6-desaturase), Delta6-fatty acyl-CoA desaturase, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyunsaturated Fatty Acid
Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic property. Polyunsaturated fatty acids can be classified in various groups by their chemical structure: * methylene-interrupted polyenes * conjugated fatty acids * other PUFAs Based on the length of their carbon backbone, they are sometimes classified in two groups: * short chain polyunsaturated fatty acids (SC-PUFA), with 18 carbon atoms * long-chain polyunsaturated fatty acids (LC-PUFA) with 20 or more carbon atoms Dietary sources Types Methylene-interrupted polyenes These fatty acids have 2 or more ''cis'' double bonds that are separated from each other by a single methylene bridge (--). This form is also sometimes called a ''divinylmethane pattern''. The essential fatty acids are all omega-3 and -6 methylene-interrupted fatty ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esterification
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unsaturated Fatty Acids
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food. The term often refers specifically to triglycerides (triple esters of glycerol), that are the main components of vegetable oils and of fatty tissue in animals; or, even more narrowly, to triglycerides that are solid or semisolid at room temperature, thus excluding oils. The term may also be used more broadly as a synonym of lipid—any substance of biological relevance, composed of carbon, hydrogen, or oxygen, that is insoluble in water but soluble in non-polar solvents. In this sense, besides the triglycerides, the term would include several other types of compounds like mono- and diglycerides, phospholipids (such as lecithin), sterols (such as cholesterol), waxes (such as beeswax), and free fatty acids, which are usually present in human diet in smaller amounts. Fats are one of the three main m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Fluidity
In biology, membrane fluidity refers to the viscosity of the lipid bilayer of a cell membrane or a synthetic lipid membrane. Lipid packing can influence the fluidity of the membrane. Viscosity of the membrane can affect the rotation and diffusion of proteins and other bio-molecules within the membrane, there-by affecting the functions of these things. Membrane fluidity is affected by fatty acids. More specifically, whether the fatty acids are saturated or unsaturated has an effect on membrane fluidity. Saturated fatty acids have no double bonds in the hydrocarbon chain, and the maximum amount of hydrogen. The absence of double bonds decreases fluidity, making the membrane very strong and stacked tightly. Unsaturated fatty acids have at least one double bond, creating a "kink" in the chain. The double bond increases fluidity. Membrane fluidity is also affected by cholesterol. Cholesterol can make the cell membrane fluid as well as rigid. Factors determining membrane fluidity Membra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
