The Krebs bike is called after that is discoverer, Hans Krebs. The is also known as the citric acid cycle or the tricarboxylic acid cycle. It is a series of chemistry reactions required for cellular respiration; it involves redox, dehydration, hydration, and also decarboxylation reaction that create ATP (adenosine triphosphate), a coenzyme energy carrier because that cells. The garbage product, in the kind of carbon dioxide, is also produced and also further to adjust of reactants offered to regenerate the original reaction.

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Glycolysis, Pyruvate Oxidation and also the Krebs Cycle

Glycolysis, the procedure of dividing a six-carbon glucose molecule into two three-carbon pyruvate molecules, is attached to the Krebs cycle. For each glucose molecule respired, the bicycle reactions take place twice as two pyruvic mountain molecules space formed. Glycolysis is an anaerobic reaction which occurs in the cytoplasm the the cell. The rest of the reaction in to move respiration space aerobic, as such requiring oxygen, and occur in the mitochondria that the cell. The three-carbon pyruvic acid molecules are converted to a two-carbon molecule attached to Coenzyme A, referred to as acetyl CoA, via the procedure of pyruvate oxidation. It is the product, acetyl CoA, i m sorry enters the Krebs cycle.


Chemical plan of Krebs bike - tricarboxylic acid (citric) cycle, 2d illustration. Photo Credit: Chromatos / Shutterstock

Steps in the Krebs Cycle

The Krebs cycle is a closed-loop set of reaction in eight steps:

The two-carbon acetyl CoA is linked with a four-carbon oxaloacetic acid and hydrolyzed to develop a six-carbon compound called citric mountain or citrate.Citrate is climate converted right into isocitrate, a six-carbon isomer that citrate by dehydrating and then hydrating the molecule come reshuffle the structure.Isocitrate is oxidized and also decarboxylation occurs through a carbon dioxide molecule released. The coenzyme NAD­+ is decreased to form another dinucleotide, NADH. With the removal of the carbon molecule, the five-carbon molecule α-ketoglutarate is produced.The α-ketoglutarate molecule is oxidized, NAD­+ is diminished to kind NADH and also another carbon molecule is released. The four-carbon molecule created combines v Coenzyme A, developing the stormy succinyl CoA compound.A phosphate group replaces the Coenzyme A in succinyl CoA, i beg your pardon is then moved to ADP (adenosine diphosphate) to kind ATP. The transference the the phosphate teams occurs in between GDP (guanosine diphosphate) to form GTP (guanosine triphosphate) in part cells. The four-carbon molecule that stays is dubbed succinate.

The remaining steps of the Krebs cycle regenerate oxaloacetic mountain from succinate:

Succinate is oxidized to type the four-carbon molecule referred to as fumerate. The electron carrier FAD (flavin adenin dinucleotide), is decreased to FADH2 by the transference of two hydrogen atoms.Fumerate is converted into the four-carbon molecule referred to as malate by the addition of a water molecule.The initial reactant oxaloacetic acid is regenerated by the oxidation the malate. The coenzyme NAD (nicotinamide adenine dinucleotide) is decreased to NADH by the transference that one hydrogen atom.

Products and Functions that the Krebs Cycle

For one cycle, two molecules of carbon, three molecules of NADH, one molecule that FADH2 and one molecule the ATP or GTP are produced. Each glucose molecule produces 2 molecules of acetyl CoA, sufficient for 2 cycles. These commodities can be multiply by two to produce the per-glucose yield. Though just one ATP (or GTP) is created directly per cycle, the commodities NADH and FADH2, can produce ATP (or GTP) in a further procedure of moving respiration called oxidative phosphorylation.

The main function of the Krebs cycle is to produce energy, stored and transported together ATP or GTP. The bicycle is also main to other biosynthetic reactions where the intermediates developed are compelled to make various other molecules, such as amino acids, nucleotide bases and also cholesterol. The Krebs bike is discovered in every cells that usage oxygen. Combined with the process of oxidative phosphorylation, the Krebs cycle produces the majority of power used by aerobic cells through the percent energy noted for humans being better than 95%.


Redox: The an unified name that the totally free oxidation and reduction processes. Oxidation is the obtaining of oxygen. Reduction is the ns of oxygen.Hydration: The enhancement of a water molecule.Dehydration: The subtraction of a water molecule.Decarboxylation: The removal of a carboxyl group and also the release of a carbon dioxide molecule.Isomer: two compounds with the exact same formula but a various structural arrangement of atoms.


Further Reading

last Updated: Feb 26, 2019


Written by

Shelley Farrar Stoakes

Shelley has actually a Master's degree in Human advancement from the university of Liverpool and also is at this time working on her Ph.D, researching compare primate and human skeleton anatomy. She is passionate around science interaction with a particular focus on reporting the latest scientific research news and also discoveries to a wide audience. Exterior of she research and also science writing, Shelley enjoys reading, discovering brand-new bands in her home city and going on lengthy dog walks.

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