羟基 (qiǎng jī) — hydroxyl group

Definition

A hydroxyl group: an oxygen–hydrogen (–OH) unit bonded to a molecule. It is the active, reactive site in many organic compounds, including sugars, alcohols, and drug molecules.

noun
hydroxyl group

Examples

  • 羟基。
    Zhè ge huà hé wù lǐ yǒu sān gè qiǎng jī.
    This compound has three hydroxyl groups.
  • 羟基。
    qiǎng jī Zài huà xué fǎn yìng zhōng hěn huó yuè.
    Hydroxyl groups are very reactive in chemical reactions.
  • 羟基。
    Hěn duō yào wù fēn zǐ bāo hán qiǎng jī.
    Many drug molecules contain hydroxyl groups.

Origin

Compound word
构词法gòucífǎ
偏正piānzhèngModifier + head

The first part narrows down the second: it says what kind of thing the head is.

羟qiǎnghydroxy
基jīgroup

羟 names the hydroxy quality, 基 names the group, together giving the chemical group.

Characters in this word

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 羥; 羟 is its simplified writing.

Meaning part形符xíngfú
羊羊yángsheep, goat
Sound part声符shēngfú
巠
巠jīng羥
The sound has drifted apartThe sound part was a clue two thousand years ago — it often still helps, but not always.

The traditional form 羥 pairs 羊 (sheep, goat) with 巠 as a sound part; the simplified 羟 is a shorthand.

Open 羟 →

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

Meaning part形符xíngfú
土土tǔearth
Sound part声符shēngfú
其
其qí基jī
Same sound today

The lower 土 means earth, and the upper 其 gives the sound; together they form the idea of a foundation of earth.

Open 基 →

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