Pyruvate dehydrogenase complexPyruvate dehydrogenase complex (PDC) is a complex of three enzymes that converts pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. Acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the glycolysis metabolic pathway to the citric acid cycle. Pyruvate decarboxylation is also known as the "pyruvate dehydrogenase reaction" because it also involves the oxidation of pyruvate.
CyanocobalaminCyanocobalamin is a form of vitamin B12 used to treat vitamin B12 deficiency except in the presence of cyanide toxicity. The deficiency may occur in pernicious anemia, following surgical removal of the stomach, with fish tapeworm, or due to bowel cancer. It is less preferred than hydroxocobalamin for treating vitamin B12 deficiency. Some study have shown that it has an antihypotensive effect. It is used by mouth, by injection into a muscle, or as a nasal spray. Cyanocobalamin is generally well tolerated.
Pyridoxal phosphatePyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependent activities, corresponding to ~4% of all classified activities. The versatility of PLP arises from its ability to covalently bind the substrate, and then to act as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates.
AzotobacterAzotobacter is a genus of usually motile, oval or spherical bacteria that form thick-walled cysts (and also has hard crust) and may produce large quantities of capsular slime. They are aerobic, free-living soil microbes that play an important role in the nitrogen cycle in nature, binding atmospheric nitrogen, which is inaccessible to plants, and releasing it in the form of ammonium ions into the soil (nitrogen fixation). In addition to being a model organism for studying diazotrophs, it is used by humans for the production of biofertilizers, food additives, and some biopolymers.
Keto acidIn organic chemistry, keto acids or ketoacids (also called oxo acids or oxoacids) are organic compounds that contain a carboxylic acid group () and a ketone group (). In several cases, the keto group is hydrated. The alpha-keto acids are especially important in biology as they are involved in the Krebs citric acid cycle and in glycolysis. Common types of keto acids include: Alpha-keto acids, alpha-ketoacids, or 2-oxoacids have the keto group adjacent to the carboxylic acid.
Flavin mononucleotideFlavin mononucleotide (FMN), or riboflavin-5′-phosphate, is a biomolecule produced from riboflavin (vitamin B2) by the enzyme riboflavin kinase and functions as the prosthetic group of various oxidoreductases, including NADH dehydrogenase, as well as cofactor in biological blue-light photo receptors. During the catalytic cycle, a reversible interconversion of the oxidized (FMN), semiquinone (FMNH•), and reduced (FMNH2) forms occurs in the various oxidoreductases.
AuxotrophyAuxotrophy (αὐξάνω "to increase"; τροφή "nourishment") is the inability of an organism to synthesize a particular organic compound required for its growth (as defined by IUPAC). An auxotroph is an organism that displays this characteristic; auxotrophic is the corresponding adjective. Auxotrophy is the opposite of prototrophy, which is characterized by the ability to synthesize all the compounds needed for growth. Prototrophic cells (also referred to as the 'wild type') are self sufficient producers of all required metabolites (e.
Isocitrate dehydrogenaseIsocitrate dehydrogenase (IDH) () and () is an enzyme that catalyzes the oxidative decarboxylation of isocitrate, producing alpha-ketoglutarate (α-ketoglutarate) and CO2. This is a two-step process, which involves oxidation of isocitrate (a secondary alcohol) to oxalosuccinate (a ketone), followed by the decarboxylation of the carboxyl group beta to the ketone, forming alpha-ketoglutarate. In humans, IDH exists in three isoforms: IDH3 catalyzes the third step of the citric acid cycle while converting NAD+ to NADH in the mitochondria.
Serine hydroxymethyltransferaseSerine hydroxymethyltransferase (SHMT) is a pyridoxal phosphate (PLP) (Vitamin B6) dependent enzyme () which plays an important role in cellular one-carbon pathways by catalyzing the reversible, simultaneous conversions of L-serine to glycine and tetrahydrofolate (THF) to 5,10-Methylenetetrahydrofolate (5,10-CH2-THF). This reaction provides the largest part of the one-carbon units available to the cell.
ReductaseA reductase is an enzyme that catalyzes a reduction reaction. 5α-Reductase 5β-Reductase Dihydrofolate reductase HMG-CoA reductase Methemoglobin reductase Ribonucleotide reductase Thioredoxin reductase E.
