Krebs cycle


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Krebs cycle

 (krĕbz)
n.
A series of enzymatic reactions in aerobic organisms involving oxidative metabolism of acetyl units and producing high-energy phosphate compounds such as ATP, which serve as the main source of cellular energy. Also called citric acid cycle, tricarboxylic acid cycle.

[After Sir Hans Adolf Krebs.]

Krebs cycle

n
(Biochemistry) a stage of tissue respiration: a series of biochemical reactions occurring in mitochondria in the presence of oxygen by which acetate, derived from the breakdown of foodstuffs, is converted to carbon dioxide and water, with the release of energy. Also called: citric acid cycle or tricarboxylic acid cycle

Krebs′ cy`cle


n.
the metabolic sequence of enzyme-driven reactions by which carbohydrates, proteins, and fatty acids produce carbon dioxide, water, and ATP.
[1940–45; after H. A. Krebs]

Krebs cycle

A series of chemical reactions in most aerobic organisms in which cells break down glucose and other molecules in the presence of oxygen to produce carbon dioxide and energy in the form of ATP. The Krebs cycle occurs in the mitochondria of all organisms except bacteria. Also called citric acid cycle.

Krebs cycle

(or citric acid cycle) A series of biochemical reactions in living cells that break down carbohydrates, releasing energy. See catabolism, metabolism.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.Krebs cycle - in all plants and animals: a series of enzymatic reactions in mitochondria involving oxidative metabolism of acetyl compounds to produce high-energy phosphate compounds that are the source of cellular energy
metabolic process, metabolism - the organic processes (in a cell or organism) that are necessary for life
biological process, organic process - a process occurring in living organisms
oxidative phosphorylation - an enzymatic process in cell metabolism that synthesizes ATP from ADP
References in periodicals archive ?
Cutaneous leiomyomas are usually caused by mutations in the gene located on chromosome 1q42.2 that encodes "Fumarate Hydratase", a Krebs cycle enzyme responsible for the conversion of fumarate to malate.3 Pilar leiomyomas are the most common type of leiomyomas and range from 2-20mm in diameter.
Further experiments in cells demonstrated that the activated enzyme was altering the Krebs cycle, a central component of cell metabolism.
Briefly, this complex enhances the enzymatic activities of Krebs cycle enzymes, isocitrate dehydrogenase, [alpha]-ketoglutarate dehydrogenase, succinate dehydrogenase, and malate dehydrogenase and mitochondrial respiratory enzymes, complex I, complex II, complex III, and complex IV.
In mitochondria, in the process of [beta]-oxidation, acyl-CoA is oxidized into several molecules of acetyl-CoA that may be used in the Krebs cycle. In order to access the Krebs cycle, the acetyl-CoA needs the presence of oxaloacetate, whose concentration decreases when carbohydrates are not available.
More specifically, you can thank the citric acid cycle, or, the Krebs cycle (as my inner biology student somehow remembers it), for this energy expenditure.
Many studies report on the antioxidant properties of alpha-ketoglutarate (AKG) which is an important intermediate in the Krebs cycle. Primarily, protective effects of AKG were established in vitro systems.
Alpha-ketoglutarate (AKG), an anion of alpha-ketoglutaric acid, is an important intermediate in the Krebs cycle, which couples amino acid metabolism with glucose oxidation.
First introduced in the 1950s because it was thought that psoriasis was caused by a biochemical defect of the citric acid (Krebs) cycle, evidence suggests that it has nothing to do with the Krebs cycle, and the major active compound appears to be dimethyl fumarate.
Pyruvate can enter 3 alternative metabolic pathways: 1) the mitochondrial Krebs cycle, 2) conversion to lactate in the cell cytosol, or 3) conversion back to glucose in the process of gluconeogenesis.
I tell them not to worry about learning the Krebs cycle (whatever that is), but instead to look at old exam questions that might be reused by a tester too burnt out or demented to write new ones.
The intermediate is oxidized in Krebs cycle, and for every two carbons that enter as acetyl-CoA, two carbons are lost as C[O.sub.2] (Eastmond & Graham, 2001; Nelson & Cox, 2009).
Unlike a medical student, you are not expected to know the Krebs cycle. Unlike the upper year, you do not have to know how to handle a hypertensive emergency.