光合成

• Reading: こうごうせい
• Romaji: kougousei
• Kanji breakdown: 光 (kou) — light; 合 (gou) — combine; 成 (sei) — create, form
• Pronunciation: /koː.goː.seː/

Meaning

Photosynthesis. The process by which plants convert sunlight into energy.

A biology noun referring to the process where plants use sunlight, water, and carbon dioxide to produce glucose and oxygen. Learned in middle school science and commonly referenced in environmental discussions. Can be used as a suru-verb: 光合成する (to photosynthesise). Often appears alongside 二酸化炭素 (nisanka tanso, carbon dioxide) and 酸素 (sanso, oxygen).

Examples

1. 植物は光合成によって酸素を作り出す。 Plants produce oxygen through photosynthesis.
2. 光合成には太陽の光と水と二酸化炭素が必要だ。 Photosynthesis requires sunlight, water, and carbon dioxide.
3. 深海では光合成ができないため別のエネルギー源が使われる。 In the deep sea, photosynthesis is not possible, so other energy sources are used.

Usage Guide

Context: biology, science education, environment

Tone: neutral

Origin & History

From Sino-Japanese: 光 (kou, light) + 合成 (gousei, synthesis/composition). Literally 'light synthesis' — creating substances using the energy of light. A direct calque of the Greek-derived 'photosynthesis.'

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal