Dehydrogenase
Encyclopedia
A dehydrogenase is an enzyme
that oxidises a substrate
by a reduction reaction that transfers one or more hydride
s (H−) to an electron acceptor, usually NAD+
/NADP+ or a flavin coenzyme such as FAD
or FMN
.
TCA cycle examples:
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that oxidises a substrate
Substrate (biochemistry)
In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...
by a reduction reaction that transfers one or more hydride
Hydride
In chemistry, a hydride is the anion of hydrogen, H−, or, more commonly, a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties. In compounds that are regarded as hydrides, hydrogen is bonded to a more electropositive element or group...
s (H−) to an electron acceptor, usually NAD+
Nicotinamide adenine dinucleotide
Nicotinamide adenine dinucleotide, abbreviated NAD, is a coenzyme found in all living cells. The compound is a dinucleotide, since it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine base and the other nicotinamide.In metabolism, NAD is involved...
/NADP+ or a flavin coenzyme such as FAD
FAD
In biochemistry, flavin adenine dinucleotide is a redox cofactor involved in several important reactions in metabolism. FAD can exist in two different redox states, which it converts between by accepting or donating electrons. The molecule consists of a riboflavin moiety bound to the phosphate...
or FMN
FMN
FMN may refer to several things:* Flavin mononucleotide.* Forsvarsministeriet, the Danish Ministry of Defence.* Four Corners Regional Airport outside Farmington, New Mexico, its IATA airport code.* Fluid Music....
.
Examples
- aldehyde dehydrogenaseAldehyde dehydrogenaseAldehyde dehydrogenases are a group of enzymes that catalyse the oxidation of aldehydes.- Function :Aldehyde dehydrogenase is a polymorphic enzyme responsible for the oxidation of aldehydes to carboxylic acids, which leave the liver and are metabolized by the body’s muscle and heart...
- acetaldehyde dehydrogenaseAcetaldehyde dehydrogenaseAcetaldehyde dehydrogenases are dehydrogenase enzymes which catalyze the conversion of acetaldehyde into acetic acid. The oxidation of acetaldehyde to acetate can be summarized as follows:...
- alcohol dehydrogenaseAlcohol dehydrogenaseAlcohol dehydrogenases are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide...
- glutamate dehydrogenaseGlutamate dehydrogenaseGlutamate dehydrogenase is an enzyme, present in most microbes and the mitochondria of eukaryotes, as are some of the other enzymes required for urea synthesis, that converts glutamate to α-Ketoglutarate, and vice versa. In animals, the produced ammonia is, however, usually bled off to the urea...
(an enzyme that can convert glutamate to α-Ketoglutarate and vice versa). - lactate dehydrogenaseLactate dehydrogenaseLactate dehydrogenase is an enzyme present in a wide variety of organisms, including plants and animals.Lactate dehydrogenases exist in four distinct enzyme classes. Two of them are cytochrome c-dependent enzymes, each acting on either D-lactate or L-lactate...
- pyruvate dehydrogenasePyruvate dehydrogenasePyruvate dehydrogenase complex is a complex of three enzymes that transform 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...
(a common enzyme that feeds the TCA CycleCitric acid cycleThe citric acid cycle — also known as the tricarboxylic acid cycle , the Krebs cycle, or the Szent-Györgyi-Krebs cycle — is a series of chemical reactions which is used by all aerobic living organisms to generate energy through the oxidization of acetate derived from carbohydrates, fats and...
in converting Pyruvate to Acetyl CoA) - glucose-6-phosphate dehydrogenaseGlucose-6-phosphate dehydrogenaseGlucose-6-phosphate dehydrogenase is a cytosolic enzyme in the pentose phosphate pathway , a metabolic pathway that supplies reducing energy to cells by maintaining the level of the co-enzyme nicotinamide adenine dinucleotide phosphate...
(involved in the pentose phosphate pathwayPentose phosphate pathwayThe pentose phosphate pathway is a process that generates NADPH and pentoses . There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars...
) - glyceraldehyde-3-phosphate dehydrogenase (involved in glycolysisGlycolysisGlycolysis is the metabolic pathway that converts glucose C6H12O6, into pyruvate, CH3COCOO− + H+...
) - sorbitol dehydrogenaseSorbitol dehydrogenaseSorbitol dehydrogenase is a protein. In humans this protein is encoded by the SORD gene.Sorbitol dehydrogenase is an enzyme in carbohydrate metabolism converting sorbitol, the sugar alcohol form of glucose, into fructose. Together with aldose reductase, it provides a way for the body to produce...
TCA cycle examples:
- isocitrate dehydrogenaseIsocitrate dehydrogenaseIsocitrate dehydrogenase and , also known as IDH, is an enzyme that participates in the citric acid cycle. It catalyzes the third step of the cycle: the oxidative decarboxylation of isocitrate, producing alpha-ketoglutarate and CO2 while converting NAD+ to NADH...
- alpha-ketoglutarate dehydrogenase
- succinate dehydrogenase
- malate dehydrogenaseMalate dehydrogenaseMalate dehydrogenase is an enzyme in the citric acid cycle that catalyzes the conversion of malate into oxaloacetate and vice versa...