cysteine

See also: Cysteine and cystéine

English

Etymology

An alteration of cystine, see -eine.

Pronunciation

• (Received Pronunciation) IPA^(key): /ˈsɪs.təˌiːn/, /ˈsɪs.tə.ɪn/, /ˈsɪs.tiˌiːn/, /ˈsɪs.ti.ɪn/
• (General American) IPA^(key): /ˈsɪs.təˌin/, /ˈsɪs.tə.ɪn/, /ˈsɪs.tiˌin/, /ˈsɪs.ti.ɪn/, /ˈsɪˌstin/

• Audio (Southern England); /ˈsɪs.ti.iːn/:

  (file)

• Rhymes: -ɪstin
• Hyphenation: cys‧te‧ine

Noun

cysteine (countable and uncountable, plural cysteines)

Skeletal formula of L-cysteine.

Skeletal formula of D-cysteine.

1. (biochemistry) A sulphur-containing nonessential amino acid C₃H₇NO₂S found in most animal proteins; it readily oxidizes to cystine.

Usage notes

When used as the name of a substance, this noun is uncountable, but when used as the name of individual molecules, it is countable.

Synonyms

• E910 when used as a food additive
• E920 when used as an improving agent
• Cys when viewed as a monomer in proteins

Derived terms

• acetylcysteine
• cysteic
• cysteinal
• cysteinate
• cysteineless
• cysteinyl
• dacisteine
• dicysteine
• glutamylcysteine
• guaisteine
• intercysteine
• isoprenylcysteine
• mecysteine
• moguisteine
• nitrosocysteine
• polycysteine
• selenocysteine
• tetracysteine
• thiocysteine

Related terms

• homocysteine

Translations

nonessential amino acid

• Bulgarian: цистеин m (cistein)
• Catalan: cisteïna f
• Chinese:

  Mandarin: 半胱氨酸 (zh) (bànguāng'ānsuān)

• Czech: cystein m
• Danish: cystein
• Esperanto: cisteino
• Finnish: kysteiini
• French: cystéine (fr) f
• Galician: cisteína f
• German: Cystein (de) n
• Greek: κυστεΐνη (el) f (kysteḯni)
• Hungarian: cisztein (hu)
• Italian: cisteina (it)
• Japanese: システイン (shisutein)
• Kazakh: цистеин (sistein)
• Kyrgyz: цистеин (tsistein)
• Mongolian: цистейн (cistejn)
• Persian: سیستئین (siste'in)
• Polish: cysteina (pl) f
• Portuguese: cisteína
• Romanian: cisteină f
• Russian: цистеи́н (ru) m (cisteín)
• Spanish: cisteína (es) f
• Swedish: cystein (sv)