Biological carbon fixation or сarbon assimilation is the process by which inorganic carbon is converted to organic compounds by living organisms. The compounds are then used to store energy and as structure for other biomolecules. Carbon is primarily fixed through photosynthesis, but some organisms use a process called chemosynthesis in the absence of sunlight.
Oxaloacetic acid (also known as oxalacetic acid or OAA) is a crystalline organic compound with the chemical formula HO2CC(O)CH2CO2H. Oxaloacetic acid, in the form of its conjugate base oxaloacetate, is a metabolic intermediate in many processes that occur in animals. It takes part in gluconeogenesis, the urea cycle, the glyoxylate cycle, amino acid synthesis, fatty acid synthesis and the citric acid cycle.
In molecular biology, biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism.
The glyoxylate cycle, a variation of the tricarboxylic acid cycle, is an anabolic pathway occurring in plants, bacteria, protists, and fungi. The glyoxylate cycle centers on the conversion of acetyl-CoA to succinate for the synthesis of carbohydrates. In microorganisms, the glyoxylate cycle allows cells to use two carbons, such as acetate, to satisfy cellular carbon requirements when simple sugars such as glucose or fructose are not available. The cycle is generally assumed to be absent in animals, with the exception of nematodes at the early stages of embryogenesis. In recent years, however, the detection of malate synthase (MS) and isocitrate lyase (ICL), key enzymes involved in the glyoxylate cycle, in some animal tissue has raised questions regarding the evolutionary relationship of enzymes in bacteria and animals and suggests that animals encode alternative enzymes of the cycle that differ in function from known MS and ICL in non-metazoan species.
In biochemistry, mixed acid fermentation is the metabolic process by which a six-carbon sugar is converted into a complex and variable mixture of acids. It is an anaerobic (non-oxygen-requiring) fermentation reaction that is common in bacteria. It is characteristic for members of the Enterobacteriaceae, a large family of Gram-negative bacteria that includes E. coli.
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 to form triglycerides, 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.
Lipstatin is a potent, irreversible inhibitor of pancreatic lipase. It is a natural product that was first isolated from the actinobacterium Streptomyces toxytricini.
Crotonyl-coenzyme A is an intermediate in the fermentation of butyric acid, and in the metabolism of lysine and tryptophan. It is important in the metabolism of fatty acids and amino acids.
In enzymology, an acyl-CoA dehydrogenase (NADP+) (EC 1.3.1.8) is an enzyme that catalyzes the chemical reaction
Cinnamoyl-CoA reductase (EC 1.2.1.44), systematically named cinnamaldehyde:NADP+ oxidoreductase (CoA-cinnamoylating) but commonly referred to by the acronym CCR, is an enzyme that catalyzes the reduction of a substituted cinnamoyl-CoA to its corresponding cinnamaldehyde, utilizing NADPH and H+ and releasing free CoA and NADP+ in the process. Common biologically relevant cinnamoyl-CoA substrates for CCR include p-coumaroyl-CoA and feruloyl-CoA, which are converted into p-coumaraldehyde and coniferaldehyde, respectively, though most CCRs show activity toward a variety of other substituted cinnamoyl-CoA's as well. Catalyzing the first committed step in monolignol biosynthesis, this enzyme plays a critical role in lignin formation, a process important in plants both for structural development and defense response.
In enzymology, a 2-oxopropyl-CoM reductase (carboxylating) (EC 1.8.1.5) is an enzyme that catalyzes the chemical reaction
Fatty-acyl-CoA Synthase, or more commonly known as yeast fatty acid synthase, is an enzyme complex responsible for fatty acid biosynthesis, and is of Type I Fatty Acid Synthesis (FAS). Yeast fatty acid synthase plays a pivotal role in fatty acid synthesis. It is a 2.6 MDa barrel shaped complex and is composed of two, unique multi-functional subunits: alpha and beta. Together, the alpha and beta units are arranged in an α6β6 structure. The catalytic activities of this enzyme complex involves a coordination system of enzymatic reactions between the alpha and beta subunits. The enzyme complex therefore consists of six functional centers for fatty acid synthesis.
Cobalamin biosynthesis is the process by which bacteria and archea make cobalamin, vitamin B12. Many steps are involved in converting aminolevulinic acid via uroporphyrinogen III and adenosylcobyric acid to the final forms in which it is used by enzymes in both the producing organisms and other species, including humans who acquire it through their diet.
In molecular biology, the HMG-CoA reductase family is a family of enzymes which participate in the mevalonate pathway, the metabolic pathway that produces cholesterol and other isoprenoids.
3-hydroxypropionate dehydrogenase (NADP+) (EC 1.1.1.298) is an enzyme with systematic name 3-hydroxypropionate:NADP+ oxidoreductase. This enzyme catalyses the following chemical reaction
Eugenol synthase (EC 1.1.1.318, LtCES1, EGS1, EGS2) is an enzyme with systematic name eugenol:NADP+ oxidoreductase (coniferyl ester reducing). This enzyme catalyses the following chemical reaction: eugenol + a carboxylate + NADP+ a coniferyl ester + NADPH + H+
Malonyl CoA reductase (malonate semialdehyde-forming) (EC 1.2.1.75, NADP-dependent malonyl CoA reductase, malonyl CoA reductase (NADP)) is an enzyme with systematic name malonate semialdehyde:NADP+ oxidoreductase (malonate semialdehyde-forming). This enzyme catalyse the following chemical reaction
Succinate-semialdehyde dehydrogenase (acylating) (EC 1.2.1.76, succinyl-coA reductase, coenzyme-A-dependent succinate-semialdehyde dehydrogenase) is an enzyme with systematic name succinate semialdehyde:NADP+ oxidoreductase (CoA-acylating). This enzyme catalyses the following chemical reaction
Acrylyl-CoA reductase (NADPH) (EC 1.3.1.84) is an enzyme with systematic name propanoyl-CoA:NADP+ oxidoreductase. This enzyme catalyses the following chemical reaction
Crotonyl-CoA reductase (EC 1.3.1.86, butyryl-CoA dehydrogenase, butyryl dehydrogenase, unsaturated acyl-CoA reductase, ethylene reductase, enoyl-coenzyme A reductase, unsaturated acyl coenzyme A reductase, butyryl coenzyme A dehydrogenase, short-chain acyl CoA dehydrogenase, short-chain acyl-coenzyme A dehydrogenase, 3-hydroxyacyl CoA reductase, butanoyl-CoA:(acceptor) 2,3-oxidoreductase, CCR) is an enzyme with systematic name butanoyl-CoA:NADP+ 2,3-oxidoreductase. This enzyme catalyses the following chemical reaction
