cysteine
cys·te·ine/ˈsɪs.təˌiːn/noun
cysteine is spelled C-Y-S-T-E-I-N-E: 8 letters and 3 syllables (cys·te·ine). It appears about once in every 2 million words in written English, the 43,663rd most frequent word form (wordfreq, 2021 data). As a noun, cysteine means “A sulphur-containing nonessential amino acid C₃H₇NO₂S found in most animal proteins; it readily oxidizes to cystine” (English Wiktionary, September 2026). The plural of cysteine is cysteines.
How many letters and syllables are in cysteine?
| Letters | 8: C-Y-S-T-E-I-N-E |
|---|---|
| Syllables | 3: cys·te·ine |
| In writing | about once in every 2 million words; the 43,663rd most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is cysteine?
Cysteine appears about once in every 2 million words in written English, the 43,663rd most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce cysteine?
- UK /ˈsɪs.təˌiːn/
- UK /ˈsɪs.tə.ɪn/
- UK /ˈsɪs.tiˌiːn/
Cysteine has 3 syllables, split cys·te·ine in writing.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-cysteine.wav, Wikimedia Commons (author and licence on each file's page).
Forms of cysteine
- cysteines plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does cysteine mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
A sulphur-containing nonessential amino acid C₃H₇NO₂S found in most animal proteins; it readily oxidizes to cystine.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Cysteine in Spanish, French, German and Portuguese
In the sense nonessential amino acid:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does cysteine come from?
An alteration of cystine, see -eine.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).