photosynthesis

noun
pho·​to·​syn·​the·​sis | \ ˌfō-tō-ˈsin(t)-thə-səs How to pronounce photosynthesis (audio) \

Definition of photosynthesis

: synthesis of chemical compounds with the aid of radiant energy and especially light especially : formation of carbohydrates from carbon dioxide and a source of hydrogen (such as water) in the chlorophyll-containing cells (as of green plants) exposed to light

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Other Words from photosynthesis

photosynthesize \ ˌfō-​tō-​ˈsin(t)-​thə-​ˌsīz How to pronounce photosynthesize (audio) \ intransitive verb
photosynthetic \ ˌfō-​tō-​sin-​ˈthe-​tik How to pronounce photosynthetic (audio) \ adjective
photosynthetically \ ˌfō-​tō-​sin-​ˈthe-​ti-​k(ə-​)lē How to pronounce photosynthetically (audio) \ adverb

Photosynthesis Has Greek Roots

The Greek roots of photosynthesis combine to produce the basic meaning "to put together with the help of light". Photosynthesis is what first produced oxygen in the atmosphere billions of years ago, and it's still what keeps it there. Sunlight splits the water molecules (made of hydrogen and oxygen) held in a plant's leaves and releases the oxygen in them into the air. The leftover hydrogen combines with carbon dioxide to produce carbohydrates, which the plant uses as food—as do any animals or humans who might eat the plant.

Examples of photosynthesis in a Sentence

Recent Examples on the Web

Nitrogen is an essential nutrient for photosynthesis and growth, so returning as much of it to the tree as possible before a leaf falls helps ensure that the plant is well-stocked for next year’s cycle. Emily Toomey, Smithsonian, "Watch Leaves Change Color in a Matter of Seconds," 14 Aug. 2019 The poop draws gnats and stinging insects, and leads to reduced photosynthesis and plant vigor. Claire Marie Porter, WIRED, "This Voracious, Unstoppable Bug Is Killing Off Vineyards," 2 Aug. 2019 Some scientists are less confident about using carbonyl sulfide as a method to measure photosynthesis. Sarah Gibbens, National Geographic, "Plants help absorb our carbon, but for how much longer?," 16 May 2019 Meadows and her collaborators have studied some alternatives to oxygenic photosynthesis. Quanta Magazine, "Scientists Debate Signatures of Alien Life," 2 Feb. 2016 Nearly all free oxygen in the air is produced by plants through photosynthesis. Scott Denning, Scientific American, "Destructive Amazon Fires Do Not Threaten Earth’s Oxygen, Expert Says," 27 Aug. 2019 Plants are green because their leaves contain chlorophyll, a pigment that reflects the green light in the middle of the spectrum while absorbing and using for photosynthesis the blue and red wavelengths at either end of it. The Economist, "New ways to make vertical farming stack up," 29 Aug. 2019 Nearly all free oxygen in the air is produced by plants through photosynthesis. Scott Denning, Scientific American, "Destructive Amazon Fires Do Not Threaten Earth’s Oxygen, Expert Says," 27 Aug. 2019 Nearly all free oxygen in the air is produced by plants through photosynthesis. The Conversation, oregonlive.com, "Amazon fires are alarming -- but, no, they won’t deplete Earth’s oxygen: The Conversation," 26 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'photosynthesis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of photosynthesis

1898, in the meaning defined above

History and Etymology for photosynthesis

New Latin

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Statistics for photosynthesis

Last Updated

13 Oct 2019

Look-up Popularity

Time Traveler for photosynthesis

The first known use of photosynthesis was in 1898

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More Definitions for photosynthesis

photosynthesis

noun

English Language Learners Definition of photosynthesis

biology : the process by which a green plant turns water and carbon dioxide into food when the plant is exposed to light

photosynthesis

noun
pho·​to·​syn·​the·​sis | \ ˌfō-tə-ˈsin-thə-səs How to pronounce photosynthesis (audio) \

Kids Definition of photosynthesis

: the process by which green plants and a few other organisms (as some protists) form carbohydrates from carbon dioxide and water in the presence of light

Other Words from photosynthesis

photosynthetic \ -​sin-​ˈthe-​tik \ adjective photosynthetic activity

photosynthesis

noun
pho·​to·​syn·​the·​sis | \ ˌfōt-ō-ˈsin(t)-thə-səs How to pronounce photosynthesis (audio) \
plural photosyntheses

Medical Definition of photosynthesis

: synthesis of chemical compounds with the aid of light sometimes including the near infrared or near ultraviolet especially : 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 usually do not require the presence of light

Other Words from photosynthesis

photosynthesize \ -​ˌsīz How to pronounce photosynthesize (audio) \ also British photosynthesise intransitive verb photosynthesized also British photosynthesised; photosynthesizing also British photosynthesising
photosynthetic \ -​sin-​ˈthet-​ik How to pronounce photosynthetic (audio) \ adjective
photosynthetically \ -​i-​k(ə-​)lē How to pronounce photosynthetically (audio) \ adverb

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More from Merriam-Webster on photosynthesis

Spanish Central: Translation of photosynthesis

Nglish: Translation of photosynthesis for Spanish Speakers

Britannica.com: Encyclopedia article about photosynthesis

Comments on photosynthesis

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