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| Title |
Biological Functions of Superoxide Dismutase, Peroxide Catalase, and Thiol Peroxidase in Cyanobacteria
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| Type of Resource |
still image
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| Date Created |
2009-05-14
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| Digital Origin |
born digtal
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| Rights Statement |
http://digital.uwyo.edu/copyright.htm
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| Keyword (topic) |
Cyanobacteria
antioxidants
oxygen-evolving photosynthetic systems
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| Series Title |
Undergrauate Research Day 2009
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| Creator(s) |
Link, Matthew
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| Contributor(s) |
Herbert, Dr. Stephen
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| Publisher |
University of Wyoming
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| Place of publication |
Laramie, Wyoming
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| Language |
eng
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| Summary |
Cells maintain a homeostasis of reactive oxygen with dynamic systems of enzymes and other molecules collectively known as antioxidants. Three types of antioxidants, superoxide dismutases, catalases, and peroxidases are thought to work together in microbial cells to limit ·OH, which results from reaction between O2 - and H2O2. ·OH is a very strong oxidant capable of oxidizing most biological molecules. Cyanobacteria are an appropriate model system for studying the role played by antioxidants in oxygen-evolving photosynthetic systems. They are easy to grow and modify genetically. Synechococcus sp. PCC 7942 was used in this study because it is believed to have a single superoxide dismutase, single catalase, and single peroxidase. It is the only photosynthetic organism in which a mutant lacking superoxide dismutase has been created. SodB is an iron superoxide dismutase that may exist in association with Photosystem I in chloroplasts and cyanobacteria. SodB catalyzes the conversion of O2 - (a byproduct of photosynthesis) to H2O2. KatG is a peroxide catalase which converts H2O2 to H2O and O2, whereas TplA, a thiol peroxidase, converts H2O2 directly to H2O. The physiology of these three antioxidants was investigated with various assays and stresses on mutants, including light intensity, hydrogen peroxide, paraquat, and a superoxide dismutase assay.
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| Notes |
From - Undergraduate Research Day 2009 - Celebration of Research - Abstracts
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