Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
Tricarboxylic acid cycle
Introduction References & Edit History Quick Facts & Related Topics
Images
Diagram of the eight-step tricarboxylic acid cycle showing the sequence of metabolites from acetyl CoA through citrate, isocitrate, alpha-ketoglutarate, succinyl CoA, succinate, fumarate, malate, and oxaloacetate, with arrows indicating the flow of reactions and production of ATP, NADH, FADH2, and CO2. A biochemical flowchart shows the metabolic pathways for carbohydrate utilization, including glycolysis, the pentose phosphate pathway, and the tricarboxylic acid (TCA) cycle. The diagram traces the conversion of glucose, fructose, and glycerol through various intermediates, leading to energy production, carbon dioxide release, and biosynthesis of amino acids and porphyrins. Key steps and branches are labeled, with colored boxes highlighting biosynthetic outputs.

Tricarboxylic acid cycle: References & Edit History

Article Contributors

Primary Contributors

  • The Editors of Encyclopaedia Britannica
    Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.

Other Encyclopedia Britannica Contributors

Article History

Type Description Contributor Date
Article title updated for style. Nov 12, 2026
Invalidated site: PNAS - Variant tricarboxylic acid cycle in Mycobacterium tuberculosis : Identification of α-ketoglutarate decarboxylase. Oct 01, 2026
Add new Web site: DigitalCommons at UMaine - The Tricarboxylic Acid Cycle as a Central Regulator of the Rate of Aging: Implications for Metabolic Interventions (PDF). Nov 21, 2025
Add new Web site: DigitalCommons at UMaine - The Tricarboxylic Acid Cycle as a Central Regulator of the Rate of Aging: Implications for Metabolic Interventions (PDF). Oct 11, 2025
Add new Web site: ABC Listen - Radio National - Nijinsky and Nureyev: at the edge of a volcano. Jul 21, 2025
Add new Web site: ASM Journals - Microbiology and Molecular Biology Reviews - Tricarboxylic Acid Cycle and Glyoxylate Bypass. May 23, 2025
Add new Web site: Journal of Biological Chemistry - Regulation and function of the mammalian tricarboxylic acid cycle. Dec 06, 2024
Add new Web site: PNAS - Variant tricarboxylic acid cycle in Mycobacterium tuberculosis : Identification of α-ketoglutarate decarboxylase. Jun 21, 2024
Add new Web site: University of Washington Pressbooks - biochemistry - Tricarboxylic Acid (TCA) Cycle. Feb 26, 2024
Add new Web site: Cell Research - Krebs and an alternative TCA cycle! Dec 05, 2023
Add new Web site: Texas Tech University Health Sciences Center - Tricarboxylic acid cycle. Aug 17, 2023
Add new Web site: Chemistry LibreTexts - The Citric Acid Cycle. Jun 23, 2023
Add new Web site: Khan Academy - The citric acid cycle. Apr 28, 2023
Add new Web site: Frontiers - Frontiers in Cellular and Infection Microbiology - The Role of Tricarboxylic Acid Cycle Metabolites in Viral Infections. Feb 18, 2023
Add new Web site: Chemistry LibreTexts - The Citric Acid Cycle. Nov 18, 2022
Add new Web site: National Center for Biotechnology Information - PubMed Central - The Tricarboxylic Acid Cycle, an Ancient Metabolic Network with a Novel Twist. Sep 02, 2022
Added new Web site: How Stuff Works - Science - Krebs Cycle. Feb 06, 2009
Added new Web site: HyperPhysics - Cellular Respiration. Aug 10, 2007
Article revised. May 04, 1999
Article added to new online database. Jul 20, 1998
View Changes:
Article History
Revised:
By: