photosynthesis

noun

pho·​to·​syn·​the·​sis ˌfō-tō-ˈsin(t)-thə-səs 

: 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

photosynthesize

ˌfō-tō-ˈsin(t)-thə-ˌsīz 

intransitive verb

photosynthetic

ˌfō-tō-sin-ˈthe-tik 

adjective

photosynthetically

ˌfō-tō-sin-ˈthe-ti-k(ə-)lē 

adverb

Did you know?

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

Here on Earth, conditions have favored the evolution of organisms that can produce oxygen through photosynthesis, which uses the green pigment chlorophyll-a. —Eric Lagatta, USA TODAY, 22 Apr. 2024

The fungi in their roots (known as mycorrhizae) provide nutrition to the orchids, and, in turn, the orchids provide the fungi with carbohydrates formed through photosynthesis. —Alicia Ault, Smithsonian Magazine, 15 Feb. 2024

Below this layer, though, sunlight starts to become irrelevant, and things get weird: The water is too murky for photosynthesis, little food is available, and the fish are deeply, resoundingly strange. —WIRED, 9 Dec. 2023

There were no trees here for most of the history of life on Earth and, indeed, for most of the history of photosynthesis, Edward Schwieterman, an astrobiologist at the University of California, Riverside, told me via email. —Bruce Dorminey, Forbes, 28 Mar. 2024

Remove cloth once the heat has passed to ensure that plants can resume normal photosynthesis in full sun. —Caralin Nunes, The Arizona Republic, 18 Mar. 2024

Tracing the variations of present-day genes places photosynthesis' origin at about 3 billion years ago. —John Timmer, Ars Technica, 3 Jan. 2024

Unlike tropical coral reefs, where photosynthesis is important for growth, coral this far down must filter food particles out of the water for energy. —Christina Larson, Fortune, 19 Jan. 2024

For example, no trees or vegetables would grow without the process of photosynthesis. —Marshall Shepherd, Forbes, 2 Mar. 2024

Word History

Etymology

New Latin

First Known Use

1898, in the meaning defined above

Kids Definition

photosynthesis

noun

pho·​to·​syn·​the·​sis ˌfōt-ə-ˈsin(t)-thə-səs 

: the process by which plants and some bacteria and protists that contain chlorophyll make carbohydrates from water and from carbon dioxide in the air in the presence of light

photosynthetic

-sin-ˈthet-ik 

adjective

Medical Definition

photosynthesis

noun

pho·​to·​syn·​the·​sis ˌfōt-ō-ˈsin(t)-thə-səs 

plural photosyntheses

: 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

photosynthesize

-ˌsīz 

intransitive verb

also British photosynthesise

photosynthesized also British photosynthesised; photosynthesizing also British photosynthesising

photosynthetic

-sin-ˈthet-ik 

adjective

photosynthetically

-i-k(ə-)lē 

adverb