Energy metabolism in anaerobic eukaryotes and Earth's late oxygenation
| العنوان: | Energy metabolism in anaerobic eukaryotes and Earth's late oxygenation |
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| المؤلفون: | Verena Zimorski, Aloysius G.M. Tielens, William Martin, Marek Mentel |
| المساهمون: | Medical Microbiology & Infectious Diseases |
| المصدر: | Free Radical Biology and Medicine Free Radical Biology & Medicine Free Radical Biology and Medicine, 140, 279-294. Elsevier Inc. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | 0301 basic medicine, Hydrogenosome, Earth history, chemistry.chemical_element, Great oxidation event, Biochemistry, Euglena, Oxygen, Hydrogenosomes, Article, 03 medical and health sciences, 0302 clinical medicine, Physiology (medical), Botany, Mitosomes, Anaerobiosis, Oxidase test, biology, Chemistry, Atmosphere, Great Oxygenation Event, Chlamydomonas, Eukaryota, Metabolism, biology.organism_classification, Anoxic waters, Biological Evolution, Mitochondria, 030104 developmental biology, Eukaryote anaerobes, 13. Climate action, Energy Metabolism, Anaerobic exercise, 030217 neurology & neurosurgery |
| الوصف: | Eukaryotes arose about 1.6 billion years ago, at a time when oxygen levels were still very low on Earth, both in the atmosphere and in the ocean. According to newer geochemical data, oxygen rose to approximately its present atmospheric levels very late in evolution, perhaps as late as the origin of land plants (only about 450 million years ago). It is therefore natural that many lineages of eukaryotes harbor, and use, enzymes for oxygen-independent energy metabolism. This paper provides a concise overview of anaerobic energy metabolism in eukaryotes with a focus on anaerobic energy metabolism in mitochondria. We also address the widespread assumption that oxygen improves the overall energetic state of a cell. While it is true that ATP yield from glucose or amino acids is increased in the presence of oxygen, it is also true that the synthesis of biomass costs thirteen times more energy per cell in the presence of oxygen than in anoxic conditions. This is because in the reaction of cellular biomass with O2, the equilibrium lies very far on the side of CO2. The absence of oxygen offers energetic benefits of the same magnitude as the presence of oxygen. Anaerobic and low oxygen environments are ancient. During evolution, some eukaryotes have specialized to life in permanently oxic environments (life on land), other eukaryotes have remained specialized to low oxygen habitats. We suggest that the Km of mitochondrial cytochrome c oxidase of 0.1–10 μM for O2, which corresponds to about 0.04%–4% (avg. 0.4%) of present atmospheric O2 levels, reflects environmental O2 concentrations that existed at the time that the eukaryotes arose. Graphical abstract Image 1 Highlights • The first 1.5 billion years of life history took place without molecular oxygen. • The first eukaryotes appeared ca. 1.6 billion years ago, oxygen rose with land plants. • Eukaryotes arose and diversified with low oxygen, anaerobic ATP synthesis is ancient. • Anaerobic energy metabolism in mitochondria is common among eukaryotic lineages. • The Km of cytochrome c oxidase might reflect low environmental O2 at eukaryote origin. |
| وصف الملف: | application/pdf |
| تدمد: | 0891-5849 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::772cdd011718b506aa9577f56c9d5d91Test https://hdl.handle.net/1765/121103Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....772cdd011718b506aa9577f56c9d5d91 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 08915849 |
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