1. The compounding or building up of chemical substances under the influence of light. 2. The process by which green plants, using chlorophyll and the energy of sunlight, produce carbohydrates from water and carbon dioxide, liberating molecular oxygen in the process. [photo- + G. synthesis, a putting together]
- bacterial p. a primitive form of p. observed in some bacteria using only one photosystem and some reducing agent other than water.

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pho·to·syn·the·sis .fōt-ō-'sin(t)-thə-səs n, pl -the·ses synthesis of chemical compounds with the aid of light sometimes including the near infrared or near ultraviolet esp the formation of carbohydrates from carbon dioxide and a source of hydrogen (as water) in chlorophyll-containing cells (as of green plants) exposed to light involving a photochemical release of oxygen through the decomposition of water followed by various enzymatic synthetic reactions that usu. do not require the presence of light
pho·to·syn·the·size -.sīz also Brit pho·to·syn·the·sise vi, -sized also Brit -sised; -siz·ing also Brit -sis·ing
pho·to·syn·thet·ic -sin-'thet-ik adj
pho·to·syn·thet·i·cal·ly -i-k(ə-)lē adv

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the process whereby green plants and some bacteria manufacture carbohydrates from carbon dioxide and water, using energy absorbed from sunlight by the green pigment chlorophyll. In green plants this complex process may be summarized thus:
6CO2 + 6H2O -> C6H12O6 + 6O2

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pho·to·syn·the·sis (fo″to-sinґthə-sis) [photo- + synthesis] a chemical combination caused by the action of light; specifically the formation of carbohydrates (with release of molecular oxygen) from carbon dioxide and water in the chlorophyll tissue of plants and blue-green algae under the influence of light. In bacteria, photosynthesis employs hydrogen sulfide, molecular hydrogen, and other reduced compounds in place of water, so that molecular oxygen is not released. Cf. chemosynthesis.

Medical dictionary. 2011.

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Look at other dictionaries:

  • Photosynthesis — Pho to*syn the*sis, n. (Plant Physiol.) The process of constructive metabolism by which carbohydrates are formed from water vapor and the carbon dioxide of the air in the chlorophyll containing tissues of plants exposed to the action of light. It …   The Collaborative International Dictionary of English

  • photosynthesis — photosynthesis. См. фотосинтез. (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.

  • photosynthesis — 1898, loan translation of Ger. Photosynthese, from photo light + synthese synthesis. Another early word for it was photosyntax …   Etymology dictionary

  • photosynthesis —  Photosynthesis  Фотосинтез   Процесс образования органического вещества из углекислого газа и воды на свету при участии фотосинтетических пигментов (хлорофилл у растений, бактериохлорофилл и бактериородопсин у бактерий). В современной физиологии …   Толковый англо-русский словарь по нанотехнологии. - М.

  • photosynthesis — ► NOUN ▪ the process by which green plants use sunlight to synthesize nutrients from carbon dioxide and water. DERIVATIVES photosynthesize (also photosynthesise) verb photosynthetic adjective …   English terms dictionary

  • photosynthesis — [fōt΄ō sin′thə sis] n. [ModL: see PHOTO & SYNTHESIS] 1. the biological synthesis of chemical compounds in the presence of light 2. the production of organic substances, chiefly sugars, from carbon dioxide and water occurring in green plant cells… …   English World dictionary

  • Photosynthesis — Composite image showing the global distribution of photosynthesis, including both oceanic phytoplankton and vegetation …   Wikipedia

  • photosynthesis — photosynthetic /foh teuh sin thet ik/, adj. photosynthetically, adv. /foh teuh sin theuh sis/, n. Biol., Biochem. (esp. in plants) the synthesis of complex organic materials, esp. carbohydrates, from carbon dioxide, water, and inorganic salts,… …   Universalium

  • photosynthesis — Process by which green plants, algae, and some bacteria absorb light energy and use it to synthesize organic compounds (initially carbohydrates). In green plants, occurs in chloroplasts, that contain the photosynthetic pigments. Occurs by… …   Dictionary of molecular biology

  • photosynthesis — [[t]f ouθoʊsɪ̱nθəsɪs[/t]] N UNCOUNT Photosynthesis is the way that green plants make their food using sunlight. [TECHNICAL] …   English dictionary

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