krebs cycle
Noun: A fundamental metabolic pathway occurring in the mitochondria of all eukaryotic cells (plants and animals). It is a cyclic series of chemical reactions where acetyl groups (derived from carbohydrates, fats, and proteins) are oxidized to produce carbon dioxide, high-energy electron carriers (NADH and FADH₂), and one molecule of ATP (or GTP). These products are then used to generate the bulk of a cell's energy through the electron transport chain.
The term is used in the fields of biochemistry, cell biology, and physiology to describe this central process of aerobic cellular respiration. * The Krebs cycle is also known as the citric acid cycle or the tricarboxylic acid (TCA) cycle. * Understanding the Krebs cycle is essential for studying how cells extract energy from nutrients. * A malfunction in the enzymes of the Krebs cycle can lead to serious metabolic disorders.
- "The Krebs cycle is a major hub of metabolism, connecting the breakdown of sugars, fats, and amino acids."
- "During aerobic respiration, pyruvate is converted to acetyl-CoA, which then enters the Krebs cycle."
- "The high-energy electrons harvested by NADH and FADH₂ in the Krebs cycle are passed to the electron transport chain."
- "To turn/cycle through the Krebs cycle": A phrase used to describe the continuous, cyclic nature of the pathway.
- Each acetyl-CoA molecule causes the intermediates to turn through the Krebs cycle once.
- "Krebs cycle intermediates": Refers to the specific molecules (like citrate, isocitrate, alpha-ketoglutarate) that are formed and consumed during the cycle. These intermediates are also important for other biosynthetic pathways.
- Citric Acid Cycle (n): The most common synonym, named for the first intermediate formed (citric acid/citrate).
- Tricarboxylic Acid (TCA) Cycle (n): Another synonym, referring to the three carboxyl groups on the early intermediates.
- Krebsian (adj, rare): Pertaining to or characteristic of the Krebs cycle or Sir Hans Krebs.
- The Krebsian pathway is a cornerstone of bioenergetics.
- Citric acid cycle
- Tricarboxylic acid cycle (TCA cycle)
- Oxidative Phosphorylation: The process that follows the Krebs cycle, using the NADH and FADH₂ it produces to generate most of the cell's ATP.
- Acetyl-CoA: The key two-carbon molecule that fuels the Krebs cycle by combining with oxaloacetate.
- Mitochondrial Matrix: The location within the mitochondrion where the Krebs cycle takes place.
- 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