peroxisome

peroxisome [pər äk′si sōm΄ ]
n.
/span> PEROXIDE + -SOME3
any of a group of organelles in some cells of mammals, the leaves of plants, etc., containing enzymes that produce and then decompose hydrogen peroxide: thought to be involved in cellular metabolism

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per·ox·i·some (pə-rŏkʹsĭ-sōm') n.
A cell organelle containing enzymes, such as catalase and oxidase, that catalyze the production and breakdown of hydrogen peroxide.
  [peroxide + -some3.]   per·ox'i·somʹal (-sōʹməl) adj.

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 membrane-bound organelle occurring in the cytoplasm of eukaryotic cells (cell). Peroxisomes contain enzymes (enzyme) that oxidize certain molecules normally found in the cell, notably fatty acids (fatty acid) and amino acids (amino acid). These oxidation reactions produce hydrogen peroxide, which is the basis of the name peroxisome. However, hydrogen peroxide is potentially toxic to the cell, because it has the ability to react with many other molecules. Therefore, peroxisomes also contain enzymes such as catalase that convert hydrogen peroxide to water and oxygen, thereby neutralizing the toxicity. In this way peroxisomes provide a safe location for the oxidative metabolism of certain molecules.

      Peroxisomes have a special transporter system for taking up their enzymes from the cytoplasm. Mutations (mutation) in genes (gene) that encode the enzymes and transporter proteins (protein) of the peroxisome are responsible for a number of human diseases, including Zellweger syndrome, a congenital disorder characterized by complete absence or reduction in number of peroxisomes. Mutations giving rise to this syndrome cause copper, iron, and substances called very long chain fatty acids (fatty acid) to accumulate in the blood and in tissues, such as the liver, brain, and kidneys (kidney). Infants with Zellweger syndrome are often born with facial deformity and intellectual disability; some may have impaired vision and hearing and may experience severe gastrointestinal bleeding or liver failure. Prognosis is poor—most infants with this syndrome do not live beyond one year.

      Peroxisomes were identified and described in the 1950s as part of the pioneering work of Christian René de Duve (Duve, Christian René de), who developed cell fractionation techniques. De Duve's method separated organelles based on their sedimentation and density properties; peroxisomes are denser than other organelles. De Duve shared the 1974 Nobel Prize for Physiology or Medicine with Albert Claude (Claude, Albert) and George Palade (Palade, George E.) for this work.

John A. Cooper
 

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Universalium. 2010.

Look at other dictionaries:

  • peroxisome — peroxisome. См. пероксисома. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • peroxisome — peroxisome. = microbody (см.). (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • peroxisome — ☆ peroxisome [pər äk′si sōm΄ ] n. [< PEROXIDE + SOME3] any of a group of organelles in some cells of mammals, the leaves of plants, etc., containing enzymes that produce and then decompose hydrogen peroxide: thought to be involved in cellular… …   English World dictionary

  • Peroxisome — Peroxisomes are ubiquitous organelles in eukaryotes that participate in the metabolism of fatty acids and other metabolites. Peroxisomes have enzymes that rid the cell of toxic peroxides. They have a single lipid bilayer membrane that separates… …   Wikipedia

  • peroxisome — A membrane bound organelle occurring in many eukaryotic cells that often has an electron dense crystalline inclusion containing catalase, urate oxidase, and other oxidative enzymes relating to the formation and degradation of H2O2; though …   Medical dictionary

  • peroxisome — noun Etymology: peroxide + 3 some Date: 1965 a cytoplasmic cell organelle containing enzymes (as catalase) which act in oxidative reactions and especially in the production and decomposition of hydrogen peroxide • peroxisomal adjective …   New Collegiate Dictionary

  • Péroxisome — Peroxysome Structure d une cellule de plante, les peroxysomes sont indiqués en bleu sous la lettre i Un peroxysome est un organite cellulaire entouré par une membrane simple et ne contenant pas de matériel génétique. Par opposition à la… …   Wikipédia en Français

  • peroxisome — Organelle containing peroxidase and catalase, sometimes as a large crystal. A site of oxygen utilization, but not of ATP synthesis. In plants, associated with chloroplasts in photorespiration and considered to be part of a larger group of… …   Dictionary of molecular biology

  • peroxisome — noun An intracellular organelle found in all eukaryotes (except Archezoa) which is the source of the enzymes that catalyze the production and breakdown hydrogen peroxide, and are responsible for the oxidation of long chain fatty acids …   Wiktionary

  • peroxisome — per·oxi·some …   English syllables

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