Krebs cycle

American  

noun

Biochemistry.

1. a cycle of enzyme-catalyzed reactions in living cells that is the final series of reactions of aerobic metabolism of carbohydrates, proteins, and fatty acids, and by which carbon dioxide is produced, oxygen is reduced, and ATP is formed.

---

Krebs cycle British  

noun

1. Also called: citric acid cycle.   tricarboxylic acid cycle.  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

---

Krebs cycle Scientific  

1. A series of chemical reactions that occur in most aerobic organisms and are part of the process of aerobic cell metabolism, by which glucose and other molecules are broken down in the presence of oxygen into carbon dioxide and water to release chemical energy in the form of ATP. The Krebs cycle is the intermediate stage, occurring between glycolysis and phosphorylation, and results in the enzymatic breaking down, rearranging, and recombination of byproducts of glycolysis. The combination of glycolysis and the Krebs cycle ultimately allows 36 ATP molecules to be produced from the energy contained in one molecule of glucose and six molecules of oxygen.

2. Also called citric acid cycle

3. See more at cellular respiration

---

Etymology

Origin of Krebs cycle

First recorded in 1940–45; after H.A. Krebs

Compare meaning

How does krebs-cycle compare to similar and commonly confused words? Explore the most common comparisons:

• glycolysis vs. Krebs cycle

Example Sentences

One outcome was an increase in metabolites such as mesaconate, which participates in the Krebs cycle, a fundamental energy-producing pathway in cells.

From Science Daily • Dec. 14, 2025

The researchers hypothesized that if they could supply some of the missing succinate molecules, they might be able to restore energy production -- essentially jumpstarting the stalled mitochondrial Krebs cycle.

From Science Daily • Jan. 29, 2024

“Asking students questions like, ‘Tell me in three sentences what is the Krebs cycle in chemistry?’

From Seattle Times • Aug. 9, 2023

And with each full turn of the Krebs cycle, plants release two molecules of CO2, leaving no carbon atoms for the plant to build leaves, roots, or stems.

From Science Magazine • Jun. 7, 2023

In the next stage, the Krebs cycle, pyruvic acid that was produced during glycolysis is broken down, and energy carriers are produced.

From Textbooks • Jan. 1, 2018