Standard Lemma guide

cystine

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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  • /ˈsɪs.tiːn/
  • rhymes with -ɪstin
  • homophone: cysteine (one pronunciation)
  • homophone: Sistine

1

noun

Meaning 1

A nonessential amino acid formed by the oxidation of cysteine; it contains two cysteine residues linked by a disulfide bond.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: biochemistry, biology, chemistry, microbiology, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

a crystalline amino acid found in proteins (especially keratin); discovered in bladder stones

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: amino acid, aminoalkanoic acid

History

Etymology

From Ancient Greek κύστις (kústis, “bladder”), where it was found.

Across languages

Translations

9 source translations are retained for this English entry.

  • Bulgarian: цистин (cistin) — a nonessential amino acid
  • Chinese Mandarin: 胱氨酸 (guāngānsuān) — a nonessential amino acid
  • Esperanto: cistino — a nonessential amino acid
  • French: cystine — a nonessential amino acid
  • German: Cystin — a nonessential amino acid
  • Italian: cistina — a nonessential amino acid
  • Polish: cystyna — a nonessential amino acid
  • Slovak: cystín — a nonessential amino acid
  • Spanish: cistina — a nonessential amino acid