chloroplast

chloroplast
chloroplastic, adj.
/klawr"euh plast', klohr"-/, n. Bot.
a plastid containing chlorophyll. See diag. under cell.
[1885-90; CHLORO(PHYLL) + -PLAST]

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Microscopic, ellipsoidal organelle in a green plant cell.

It is the site of photosynthesis. It is distinguished by its green colour, caused by the presence of chlorophyll. It contains disk-shaped structures called thylakoids that make possible the formation of ATP, an energy-rich storage compound.

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 structure within a green plant cell in which photosynthesis occurs. One of three types of round, oval, or disk-shaped bodies known as plastids, chloroplasts are distinguished from the other two types (colourless leucoplasts and yellow-to-red chromoplasts) by their green colour, which results from the presence of two pigments, chlorophyll a and chlorophyll b. A function of these pigments is to absorb light energy, which is converted to chemical energy during the process of photosynthesis.

      A chloroplast is ellipsoidal, about 2.5 microns (1 micron = 0.001 millimetre) thick and 5 microns long. The chloroplast is enclosed in a double membrane, within which are the stroma (a matrix containing dissolved enzymes) and the lamellae (internal membranes folded into closed disks, the thylakoids). These disks are necessary for the formation of adenosine triphosphate (ATP), an energy-rich storage compound. In the chloroplasts of most higher plants are regions called grana (singular granum), in which the thylakoids are tightly stacked.

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Universalium. 2010.

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Look at other dictionaries:

  • Chloroplast — Chlo ro*plast, n. [Pref. chloro + Gr. ? to mold, form.] (Biol.) A plastid containing chlorophyll, developed only in cells exposed to the light. Chloroplasts are minute flattened granules, usually occurring in great numbers in the cytoplasm near… …   The Collaborative International Dictionary of English

  • chloroplast — chloroplast. См. хлоропласт. (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.

  • chloroplast — 1887, shortened from Ger. chloroplastid (1884), from CHLORO (Cf. chloro ) + PLAST (Cf. plast) …   Etymology dictionary

  • chloroplast — ► NOUN ▪ a structure in green plant cells which contains chlorophyll and in which photosynthesis takes place. ORIGIN from Greek khl ros green + plastos formed …   English terms dictionary

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  • Chloroplast — Simplified structure of a chloroplast Chloroplasts (English pronunciation: /ˈklɒrəplæsts/) are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve …   Wikipedia

  • Chloroplast — Chloroplasten in der Blattspreite des Laubmooses Plagiomnium affine …   Deutsch Wikipedia

  • chloroplast — UK [ˈklɔːrəʊplæst] / US [ˈklɔroʊˌplæst] noun [countable] Word forms chloroplast : singular chloroplast plural chloroplasts biology a part of a plant cell that contains chlorophyll and where photosynthesis takes place …   English dictionary

  • chloroplast — Photosynthetic organelle of higher plants. Lens shaped and rather variable in size but approximately 5µm long. Surrounded by a double membrane and contains circular DNA (though not enough to code for all proteins in the chloroplast). Like the… …   Dictionary of molecular biology

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